Land Management Field Manual Crow's Nest District

QE83001 CROWSCROWS NESTNEST DISTRICTDISTRICT

LANDLLANDAND MANAGEMENTMMANAGEMENTANAGEMENT FIELDFFIELDIELD MANUALMMANUALANUAL

Queensland Government Technical Report

This report is a scanned copy and some detail may be illegible or lost. Before acting on any information, readers are strongly advised to ensure that numerals, percentages and details are correct.

This report is intended to provide information only on the subject under review. There are limitations inherent in land resource studies, such as accuracy in relation to map scale and assumptions regarding socio-economic factors for land evaluation. Before acting on the information conveyed in this report, readers should ensure that they have received adequate professional information and advice specific to their enquiry.

While all care has been taken in the preparation of this report neither the Queensland Government nor its officers or staff accepts any responsibility for any loss or damage that may result from any inaccuracy or omission in the information contained herein.

For information about this report contact [email protected] Queensland Department of Primary Industries Training Series Q£83001

LAND MANAGEMENT FIELD MANUAL CROW'S NEST DISTRICT

J. Bierenbroodspot Soil Conservation Branch Major contributor

and

J.A. Mullins Development Planning Branch Editor

Queensland Department of Primary Industries Brisbane 1983 ISSN 0812-0005

None of the material contained in this publication may be abstracted or cited as a reference without the specific permission of the authors concerned.

Queensland Department of Primary Industries GPO Box 46 Brisbane 4001. (\)

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CON, �� , . . ·> . I'Vol\'o . �,. . ;, ·'·· . ' . '41.£ -�/I /,' /,

Pittsworth

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SCALE 1:1 000 000 QUEENSLAND DEPARTMENT OF PRIMARY INDUSTRIES

LEGEND CROW'S NEST SOIL CONSERVATION DISTRICT Road

Railway LOCALITY PLAN r--,

Soil Conservation Study Area L __ J

Map 1. TABLE OF CONTENTS

PAGE NO.

1. INTRODUCTION 1.1

Part I - The Land Resources

2. CLIMATE 2.1

3. GEOLOGY 3. 1

4. THE LAND RESOURCE AREAS AND AGRICULTURAL MANAGEMENT UNITS 4.1

4. 1 Land Resource Areas 4. 1

4.2 Agricultural Management Units 4. 1

4. 2.1 Introduction 4. 1 4.2.2 Marburgs Land Resource Area 4.4 4.2.3 Metamorphics Land Resource Area 4.6 4.2.4 Granites Land Resource Area 4.7 4.2.5 Basalt West Land Resource Area 4.8 4.2.6 Basalt East Land Resource Area 4.9 4.2.7 Basaltic Red Soils Land Resource Area 4.10 4.2.8 Alluvium Land Resource Area 4.12

5. LAND USE AND LAND DEGRADATION s. 1

5.1 Existing Land Use s. 1

5.2 Land Degradation 5.2

Part II - Land Management

6. LIMITATIONS AND MANAGEMENT PRACTICES FOR AGRICULTURAL PRODUCTION

6.1 Introduction 6. 1

6.2 Grain and Fodder Crops 6. 1

6.3 Horticultural Crops 6.6

6. 3.1 Sma 11 Crops 6.6 6.3.2 Tree and Vine Crops 6.6

6.4 Pastures 6.7

6. 4.1 Native Pastures 6.7 6.4.2 Improved Pastures 6.7 6.4.3 Pasture Management 6. 11 ii

PAGE NO.

7. SPECIFICATIONS FOR RUNDFF CONTROL STRUCTURES 7.1

7.1 Introduction 7. 1 7.2 Runoff Estimation 7.1 7.3 The Runoff Control Structures 7.4 7.4 Specifications for Contour Banks 7.5 7.5 Specifications for Modified Contour Banks/ Beds for Small Crops 7. 15 7. 6 Specifications for Diversion Banks 7.22 7-7 Specifications for Pondage Banks 7.26 7.8 Specifications for Spreader Channels 7.27 7.9 Specifications for Waterways 7.28 7.1 0 Specifications for Grass Strips 7-39 7.11 Specifications for Pasture Furrows 7.40

8. AGRONOMIC PRACTICES FOR EROSION CONTROL 8. 1

8.1 Introduction 8. 1 8.2 Grain and Fodder Crops 8. 1 8.3 Horticultural Crops 8.3 8.4 Pastures 8.3

9. CONSERVATION MANAGEMENT SYSTEMS 9. 1

9.1 Introduction 9. 1 9.2 Grain and Fodder Crops 9.1 9.3 Horticultural Crops 9.5

9.3. 1 Small Crops 9. 5 9.3.2 Tree and Vine Crops 9.5

9.4 Pastures 9.5

10. SPECIFICATIONS FOR SPECIAL PURPOSE LAND US E 1 0. 1

10.1 Specifications for Subdivision and Farm Amalgamation 1 0. 1 10.2 Specifications for Rehabilitation of Top Soil Quarries 1 '). 3 10.3 Specifications for Reclamation of Severely Eroded Land 10.3

11. SUMMARY OF THE MANAGEf�ENT PRACTICES FOR THE M1Us 11. 1

11. 1 Marburgs, Metamorphics and Granites Land Resource Areas1 1 . 2

11. 2 Basalt West Land Resource Area 11 • 14 11.3 Basalt East Land Resource Area 11 . 17 11.4 Basaltic Red Soils Land Resource Area 11 . 22 11 .5 Alluvium Land Resource Area 11. 30

BIBLIOGRAPHY 12. 1

APPENDICES iii

APPENDICES

Appendix 1 Detailed Soils' Information for the AMUs of the Basalt East, Basaltic �ed Soils and Alluvium LRAs -by S.E. Macnish

Appendix II Soil A�alytical Data for Representative Profiles of the Basalt East,, Basaltic Red Soils and Alluvium LRAs -by S.E. Macnish

Appendix Ill Land Capability Classification for Agriculture.

Appendix IV Determination of Rainfall Intensity for Use in the Rational Formula.

Appendix V Peak Runoff from the Inter Bank Area for a Runoff Coefficient of 0.5 for the 1:10 design frequency.

Appendix VI Design Depth of Flow for Narrow Base Contour Banks.

Appendix VII Permissible Channel Gradient and Design Depth of Flow for the Various Types of Modified Contour Banks/Beds for Small Crop areas.

Appendix VIII Furrow Velocities for a Range of Furrow Gradients in Small Crop Row Furrows.

Appendix IX Design Depth of Flow and Channel Capacity for Di,version Banks with a bottom Width of 3m.

Appendix X Bottom Width and Design Depth of Flow for \Jaterways with a Bottom Width Less than 30 m for Grain and Grazing areas.

Appendix XI Bottom Width and Depth of Flow for Waterways with a Bottom Width Greater than 30 m for Grain and Grazing areas. Ai)pendix XII Design Depth of Flow for Waterways for Small Crop Areas .

Appendix XIII Botanical Name of the Common Plant Species Listed in this Publication.

Appendix XIV Potential of the Major Pasture Species for the Grow's Nest District.

Appendix XV Research and Monitoring Projects in the Grow's Nest District (January 1982) .

I , iv

ACKNOWLEDGEMENTS

I. Officers contributing major sections:

(i) Mr. S.E. Macnish -Provision of AMUs, soil profile descriptions and soil analytical data for the Basalt East, Basaltic Red Soils and Alluvium Land Resource Areas.

Section 4.2.6 and 4.2.7 and Appendices I and I I.

I I. Officers providing technical advice and editorial assistance:

(i) Mr. J.K. Cull -information on crop and pasture management.

(i i) Dr. W.J. Scattini -information on suitable pasture species.

(i ii) Mr. G.W. Lubach - information on horticultural crop management.

(iv) Mr. A.W. Plasto -stocking rates for the AMUs.

(v) Dr. P.N. Truong -information on waterway species and maintenance.

(vi) Mr. N.M. Dawson, Mr. B.E. Vandersee and Mr. R.M. Stephens for helpful criticism and editing of the manuscript for this the first Land Management Field Manual. I - 1

1, INTRODUCTION

Farm planning for optimum production with m1n1murn degradation to the land resource requires adequate definition of specifications for production and erosion control management. These specifications should be related to a suitable soils base that is both relevant to the area of concern and easily used by the farm planner. Such information should be recorded in an easily interpreted and readily useable format and should be reviewed and updated on a regular basis.

Information in this format is required for the Grow's Nest district located in the eastern Darling Downs of Queensland (Map 1).

This Grow's Nest field manual is the first in a series of manuals which will compile the land management practices for the major cropping areas of the State. The programme was commenced in its present form in late 1979 and has as its objectives:

(i) To provide a resource base for farm planning purposes by defining the major agricultural management units (AMUs) for each District;

(ii) To provide specifications for soil conservation measures, agronomic practices and conservation management systems;

(iii) To document this material in Land Management Field Manuals; and

(iv) To continually review and update the resource base and management specifications.

The programme currently involves co-operation between Soil Conservation, Agriculture and Development Planning Branches of the Department of Primary Industries and where applicable other agricultural organisations.

The end product of the programme will be a series of land management field manuals such as this for use by Departmental officers who are aware of the constraints of the manual.

This manual identifies (Map 3) and describes the land resource areas for the Crew's Nest district, and collates all available information on the soil resources together with their current management recommendations. The material contained in this field manual will be continually reviewed and updated as better information becomes available. 2-1

2. CLI�1ATE

Detailed climatic data are presented by Cull (1972) .

The approximate isohyets which were determined from Meteorological Bureau and farmer data are shown in Map 2. Mean annual rainfall varies from 650 mm at Meringandan to 1 200 mm at Ravensbourne.

The rainfall is summer dominant. Mean monthly rainfall for selected centres are shown in Map 2.

Mean monthly maximum and minimum temperatures for ° Toowoomba are shown in Map 2. On average, temperatures exceed 32 C in only 10 days of the year. Higher temperatures are expected east and west of the Great Divide. The first frost usually occurs at the beginning of May and the last frost in mid September.

Estimated tank evaporation exceeds average annual rainfall in all months of the year with peak evaporation occurring during December and January.

The district has been subdivided into climatic zones on the basis of mean annual rainfall and mean maximum temperature for January (Map 2) . The mean annual rainfall and mean maximum January temperature for the climatic zones are shown in Map 2. Agricultural management recommendations in Part II are based on tbese climatic zones.

Erosion Index (EI ) data - both annual and monthly 30 distribution - are presented by Rosenthal and White (1980) . Annual values for the district vary from 200 to 250 depending on location. Monthly distribution for the district is presented in Figure 2.1. The high erosivity rains during the summer months (Figure 2.1) are a limitation to cropping on the highly erodible soils in the district.

·�·r------� 100 I 90 I

80 / . v 70. v./ _.. X 60 .... � "" ..-- .: c _.� 0 .....- ·;,;; ....------N e 50 ...... ' UJ v N o; � c c <( / 40 0 "' I 30 I

20 I I 10 I 0 Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

Figure 2.1 Erosion Index Distribution Curve for the Crow's Nest District (After Rosenthal and White, 1980) QUEENSLAND

DEPARTMENT OF PRIMARY INDUSTRIES

EASTERN DARLING DOWNS REGION

CROW'S NEST SOIL CONSERVATION DISTRICT

CLIMATE AND CLIMATIC ZONES

by J. Bierenbroodspot

SCALE 1:300 000

5 0 10 15 km �-.....

Drawn by S. Wallace

REFERENCE

Annual rainfall isohyet (mm)

B Climatic zone number (see below for description)

AVERAGE ANNUAL AVERAGE MAX. TEMP. CLIMATIC ZONE RAINFALL (mm) JANUARY ("C)

A1 750-950 <28

A2 >950 <28

B 750-950 28-32

c <750 28-32

BASE MAP supplied by thE! Royal Australian Survey Corps. COMPILED by J. Bierenbroodspot, Soil Conservation Branch, Division of Land Utilisation, Department of Primary Industries, Toowoomba. 27"30' 27o30PREPARED by the Drafting Branch, Division of Land Utilisation, Department of Primary Industries, Brisbane. PRINTED by the Government Printing Office, Brisbane, 1981.

' 151"45 152"00' 152"15' Map2. 3-1

3. GEOLOGY

The geology of the area has been mapped by Cranfield et al. (1976) and by Murphy et al. (1976). The geological units of these authors which give rise to similar soils have been grouped into composite geological units - see Table 3.1. The composite geological units form the basis for the land resource areas.

The geological history of the area is discussed by Mullins (1978) .

TABLE 3.1 COMPOSITE GEOLOGICAL UNITS OF THE

CROW'S NEST VISTRICT

COMPOSITE GEOLOGICAL GEOLOGICAL UNITS OF CRANFIELD MAPPING UNIT ET AL. (1976) AND MURPHY SYMBOL ET AL. (1976)

Metamorphics Sugarloaf Metamorphics Pzs Maronghi Creek Beds Pzm ( Pch Cressbrook Creek Group ( Peg ( Pc

Granites Woolshed Mountain Granodiorite Puo or Pgw Eskdale Granodiorite P-Rge Crow's Nest Granite P-Rgc Djuan Tonalite P-Rgt Undifferentiated Intrusions P-Rg Taromeo Tonalite P-Rt

Marburg Formation Tarong Beds Rt or Rut (predominantly coarse Woogaroo Sub Group R-Jo or R-Jw grained sediments) Marburg Formation Jm

Basalts Main Range Volcanics Tm Tmc

Lateritized Basalts Lateritized Main Range Volcanics

Alluvium Alluvium Czb 4-1

4. THE LAND RESOURCE AREAS AND AGRICULTURAL MANAGEMENT UNITS

4. 1 LAND RESOURCE AREAS

A land resource area (LRA) consists of a group of related soils developed on a common geology and in most cases having a similar vegetation community. Seven LRAs have been delineated:

(i) Marburgs (ii) Metamorphics (iii) Granites (iv) Basalt - West (v) Basalt - East (vi) Basaltic Red Soils (vii) Alluvium

The major occurrences of the LRAs were mapped and are presented in Map 3 at a scale of 1:250 000. A key to the LRAs based on surface soil characteristics, landform, parent material and vegetation is presented in Figure 4. 1. The distinguishing features of each LRA are summarised in Table 4. 1.

4.2 AGRICULTURAL MANAGEMENT UNITS (AMUs)

4.2. 1 Introduction

An agricultural management unit is a group of soil series/ soil phases with similar agricultural and soil conservation management requirements.

The identification of an agricultural management unit in the field requires:

(a) The identification of the Land Resource Area. The use of the key in Figure 4. 1 will aid identification of the LRA. The LRA map (Map 3) can be used as a guide to identification.

(b) The identification of the soil series/phase and thus the AMU within each LRA. Soil profile descriptions and photographs in association with the soil keys (Appendix I and Mullins 1978) will provide sufficient information for the identification of the AMUs.

A summarised profile description together with a photograph of the soil profile are provided for the Basalt East and Basaltic Red Soils LRAs. Detailed soil profile descriptions of the AMUs in these LRAs are provided in Appendix I. Soil profile descriptions and soil profile photographs of the soils of the other LRAs are presented by Mullins (1978). FIGURE 4. 1 KEY TO THE LANV RESOURCE AREAS (LRAI) OF THE CROW'S NEST VISTRICT

Plains and Valley Bottoms Strongly structured, self mulching Alluvium LRA soils, developed on basalt; predominantly on the western slopes of the main range; predominantly open forest to woodland of mountain coolibah or open forest of mountain coolibah and narrow-leaved ironbark with a scrub Predominantly black understory. �---- Basalt earths and li thosols ----i West LRA developed on basalt. Absence of sand and sandstone gravel. Weak, finely structured surface soils developed on basalt; pre dominantly on plateau remnants and dissected hills east of the Soils ..____ N main range; predominantly open I - ... forest of narrow leaved ironbark or closed forest of softwood scrub species. Basalt Predominantly krasnozems East LRA Slopes developed on laterite and and tuffaceous material. Hilltops Minor colluvial black earths occur in association. Basaltic Red Soils LRA

Presence of sand and sandstone gravel. The surface A horizon is clay loam or Marburg Formation type coarser. parent material ------Marburgs LRA

Metamorphic parent material ------Metamorphics LRA

Granite parent material ------Granites LRA 152"15'

27'00' QUEENSLAND 27"00' DEPARTMENT OF PRIMARY INDUSTRIES

EASTERN DARLING DOWNS REGION

CROW'S NEST SOIL CONSERVATION DISTRICT

LAND RESOURCE AREAS

by J. Bierenbroodspot

SCALE 1:300 000

Drawn by S. Wallace

REFERENCE

MET AMORPHICS 27'15' 27'15'

2 GRANITES

3 MARBURGS- Predominantly coarse grained sediments (includes Tarong Beds, Woogaroo Sub-Group and Marburg Formation.)

4 BASALTS-WEST

5 BASALTS- EAST

6 BASAL TIC RED SOILS

7 ALLUVIUM

BASE MAP supplied by the Royal Australian Survey Corps. COMPILED by J. Bierenbroodspot, Soil Conservation Branch, Division of Land Utilisation, Department of Primary Industries, Toowoomba. 27'30' 27•30• PREPARED by the Drafting Branch, Division of Land Utilisation, Department of Primary Industries, Brisbane. PRINTED by the Government Printing Office, Brisbane, 1981.

' 151'45 152'00' 152'15' Map3. 4-3

' Table4.1 DISTINGUISHING FEATURES OF THE LAND RESOURCE AREAS OF THE CROW SNEST DISTRICT

Features Metamorphics Granites Marburgs Basalt West Basalt East Basaltic Red Soils Alluvium

Parent Metamorphics Granites and Coarse grained Basalt Basalt Lateritized basalts Mixed alluvia derived Material granodiorites. sedime nts of the and tuff. from a range of other Marburg Formation, parent materials in Woogaroo Sub the District. Group and Tarong 13eds.

Physiogr-aphy Steep ro Undulating to Undulating to Undulating to Steep hilly to Plateaux and short Flat to gently sloping h mountainous. hilly. illy. steep. IDOuntainous with steep slopes. vall<>Y floors. short steep slopes and narrow valleys,

Soils Shallow, stony Shallow to 1Iard setting Moderately dee;:> 1ioderately deep to lloderat.,ly deep to Deep, dark,self sands and loams moderately deep loams to clay to deep, self deep, dark, crackillg deep, gradational, mulching, cracking (lithosols) and sands and learns loams overlying mulching, dark, clays (black e3rths) red soils clays (black earths) hard setting (li thosols and yellowish grey, cracking clays with weak to strong: (krasnozems) with to hard setting a friable surface. loams and clay siliceous sands) clay sub soils (black earths) very fine to fine te:Kture contrast soils loams overlying and grey sands (solOdized with fine to surface structure. Surface structure (red-brown earths, yellowish grey, to loams solonetz/ medium surface Shallow stony soils is IUOderate, medium soloclized solonetz/ clay sub soils overlying red c;olodics). structure. (lithosols) occur granular to soloOics). (solodi;;;ed and brown clay Deep sands Shallow, stony on the upper slopes structureless. solonet:z/ subsoils (red (siliceous soils (1Hhosols) and hill tops. Some dark colluvial solodics) and brown earths, sands), reddish occur on �he soils occur on lower reddish brown yellow earths brown clay loams upper stores slopes and in the depression lines. clay loams and solodized overlying red and hill tops. overlying red solonetz/ .9.Dd brown clays and brown, clay solod:ics). (red-brown earfrs sub soils (red and yellow eart� brown earths and shallow, stony and yellow earths) sands and loams (lithosols).

SIO!face Clay loam or Clay loam Clay loam Predominantly Predominantly Predominantly light Varies from heavy clay Soil coarser. or coarser. or coarser. heavy clays. heavy clays. to medium clays to sandy loam. Texture Some clay loams and clay loarns.

Vegeta-tion Open forest Open forest Layered open Open forest to Open forest to Either a Grassy open woodland to woodland to woodland of forest to woodland of woodland of layered open of Queensland blue barked of narrow grey gum and ;;hrubby woodland mountain coolibah, narrow leaved forest of white gum, or rough leaved iron narrow leaved of narrow leaved or open fares t ironbark or stringy bark, Sydney apple or silver leaved bark and grey ironbark. ironbark, gum of mountain closed forest of blue gum, ironbark. Some gum. topped box, bull coolibah and softwood scrub tallowwood and grassland. oak (west of ironbark ,;ith an species. red bloodwood with Great Divide only) underston> of an understorey of and wattles. scrub species. wattles and black Communities of she oak or a closed Queensland blue forest of Sydney gum, silver leaved blue gum and ironbark, white softwood scrub stringy bark and species or a closed grey gum occur. forest of rainforest species.

Other Soil Sand is present Sand is present Sand is present on Peds with smooth, Peds with smooth, Earthy, rough faced, Both deep, uniform clays Features on the soil on the soil the soil surface shiny faces shiny faces occur crumb structured peds and hardsetting A surface and surface and and throughout the occur throughout throughout the in the horizon loamy duplex soils. throughout throughout the soltllll. the solum. solurn. overlying a B horizon Not an extensive the soltllll. solum. with smooth, shiny soil group. faced peds. 4-4

4.2.2 Marburgs Land Resource Area

The Agricultural Management Units (AMUs) of the Marburgs LRA are separated on the four properties outlined in Table 4. 2. The AMUs are summarised according to those properties in Table 4.3. Abbreviated soil profile descriptions together with soil profile photographs for the AMUs in this LRA are presented by Vandersee in Mullins (1978). Detailed soil profile descriptions are presented by Vandersee in Vandersee and Mullins (1977).

The most commonly occurring AMUs in the district are:

FSI (TC) MF* CSI (TC) MF FSI (U) MF CSI (U) MF CMI (TC) MF CDI (TC) MF FMH (TC) MF CSH (TC) MF CMH (TC) MF CS-MP (TC) MS* FS-MP (TC) MS FS-MP (TC) MF

(*MF = Marburgs Forest; *MS = Marburgs Scrub)

Techniques for field identification of the permeability of sub soils of texture contrast soils are presented in Vandersee (1977) and Mullins (1977).

TABLE 4.2 CATEGORIES OF FOUR SOIL PROPERTIES ANV ASSOCIATEV SYMBOLS USEV TO IVENTIFY THE SOIL

UNITS OF THE MARBURGS LRA

SOIL PROPERTY CATEGORY SYMBOL

Texture of the A horizon Fine (loam to clay loam) F Coarse (coarser than loam) c

Depth of the A horizon Shallow ( < 15 em) s Moderate (15 - 30 em) M Deep ( > 30 m) D

Permeability of the Impermeable I B horizon Partially Permeable H Permeable p

Texture profile type Texture Contrast TC Gradational G Uni.form u 4-5

TABLE 4.3 AGRICULTURAL MANAGEMENT UNITS

OF THE MARBURGS LRA

A HORIZON PERMEABILITY OF TEX11JRE AMU THE B HORIZON PROFILE TYPE TEXTURE DEPTH (CM) SYMBOL

< 15 Impermeable Texture contrast FSI (TC)

Uniform FSI (U)

Partially Permeable Texture contrast FSH (TC)

Loam Partially Permeable Texture contrast FMH (TC)

to 15 - 30 Impermeable Texture contrast FMI (TC)

Clay Uniform FMI (U)

Loam > 30 Impermeable Uniform FDI (U)

Permeable Uniform FDP (U)

All Depths Permeable Texture contrast FS-MP (TC)

Gradational FS-MP (G)

< 15 Impermeable Texture contrast CSI (TC)

Uniform CSI (U)

Partially Permeable Texture contrast CSH (TC)

Coarser 15 - 30 Partially Permeable Texture contrast CMH (TC)

than Impermeable Texture contrast CMI (TC)

Loam Uniform CMI (U)

>30 Impermeable Texture contrast CDI (TC)

Uniform CDI (U)

All Depths Permeable Texture contrast CS-MP (TC)

Gradational CS-MP (G)

NOTE: (i) Profiles with shallow and moderately deep surface A horizons have been combined as one unit (FS-MP and CS-MP) . (ii) FS-MP (TC) - The texture of the surface A horizon is predominantly a clay loam. Light clays do occur. (iii) FDP (U) only occurs in the Alluvium LRA. (iv) Not all soils listed in Table 4.3 occur in the Craw's Nest District. 4-6

4.2.3 Metamorphics Land Resource Area

The AMU classification for the Marburgs LRA has been used to classify soils in the Metamorphics LRA. As for the Marburgs, AMUs have been separated on the four properties outlined in Table 4.2 and the AMUs are summarised according to these properties in Table 4.3. Abbreviated soil profile descriptions together with a soil profile photograph for the AMUs in this LRA are presented by Vandersee in Mullins (1978). Detailed soil profile descriptions are presented by Vandersee in Vandersee and Mullins (1977).

AMUs recorded in the Metamorphics LRA include:

(i) CSI (U) - M (ii) CSI (TC) - M (iii) CS-MP (TC) - M (iv) FSP (G) - M

(M = Metamorphics) . 7 4-

4.2.4 Granites Land Resource Area

The AMU classification for the Marburgs LRA has been used to classify soils in the Granites LRA. As for the Marburgs, AMUs have been separated on the four properties listed in Table 4. 2 and the AMUs are summarised according to these properties in Table 4.3. Abbreviated soil profile descriptions together with a soil profile photograph for the AMUs in this LPJl are presented by Vandersee and Mullins (1978). Detailed soil profile descriptions are presented by Vandersee in Vandersee and Mullins (1977).

AMUs recorded in the Granites LRA include:

(i) CSI (U) - Gr (ii) CMI (U) - Gr (iii) CS-MP (TC) - Gr (iv) COP (TC) - Gr*

(Gr � Granites)

* This unit does not occur in the Marburgs LRA and is not listed in Table 4.3.

------.--- . 4-8

4.2.5 Basalt West Land Resource Area

Two AMUs occur in this LRA in the Crow's Nest District:

(i) Kenmuir (ii) Purrawunda

Abbreviated soil profile descriptions together with a soil profile photograph for the AMUs are presented by Cummins and Macnish in Mullins (1978). Detailed soil profile descriptions are presented by Thompson and Beckmann (1959). 4-9

4.2.6. Basalt East Land Resource Area

Five AMUs occur in this LRA:

(i) BSs (ii) BSd (iii) BFs (iv) BFd (v) BFwd

(B = Basalt; S = Scrub; F = Forest; s = shallow soil

profile; d = deep soil profile; w = weakly structured surface soil)

An abbreviated soil profile description, a soil profile photograph and the distinguishing features for each AMU are presented in this section. Detailed soil profile descriptions and a soil key for the LRA are presented in Appendix I.

Distinguishing Features of the AMUs.

BSd Basalt scrub deep

(i) Brownish black, medium to heavy, cracking clay. (ii) Weak to moderate fine surface structure. (iii) Moderately deep to deep soil. (iv) Occurs mainly on lower slopes.

BSs Basalt scrub shallow

(i) Brownish black, clay loam to light clay. (ii) Weak, fine surface structure. (iii) Shallow stony or gravelly soil. (iv) Occurs mainly on ridges and upper slopes.

BFs Basalt forest shallow

(i) Black or brownish black, clay loam to medium clay. (ii) Weak, medium granular structure. (iii) Shallow stony or gravelly soil. (iv) Occurs mainly on ridges and upper slopes.

BFd Basalt forest deep

(i) Brownish black, medium to heavy, cracking clay. (ii) Strong granular structure. (iii) Moderately deep to deep soil. (iv) Occurs in mid and lower slope positions.

BFwd Basalt forest, weak structure, deep

(i) Brownish black, light clay; weakly cracking in virgin condition, but cracking more pronounced when cultivated. (ii) Structureless to weak, fine crumb surface. (iii) Moderately deep to deep soil. (iv) Occurs in mid and lower slope positions. 4-10

4.2.7 Basaltic Red Soils Land Resource Area

Seven AMUs occur in this LRA:

( i) Cabarlah (ii) Pechey (iii) Palmtree (i v) Geham (v) Ravensbourn e (vi) Pinelands 1 and 2 (vii) Merritts

Distinguishing Features of the AMUs.

Cabarlah

( i) Reddish brown loam to clay loam surface. (ii) Weak fine crumb surface structure. (iii) Very shallow to shallow gravelly soil, with ironstone nodules. (i v) Occurs on ridges, upper slopes and on some plateau remnants.

Geham

(i ) Dark brown, light to medium clay surface. (ii) Weak granular surface structure. (iii) Small to moderate amounts of ironstone nodules and gravels in dark A horizon. (i v) Moderately deep soil but generally poor permeability below 60 em. (v) Often associated with perched water table. (vi) Occurs in lower slopes and in broad valley floors generally below Cabarlah AMU.

Pechey

(i) Dark reddish brown, loam. (ii) Structureless, •snuffy' surface. (iii) Deep to very deep soil with some ironstone nodules and gravels (i v) Generally occurs on plateau and upper slopes. 4-11

Pinelands 1

(i) Dark reddish brown light clay. (ii) Moderate granular surface structure. (iii) Shallow to moderately deep soil overlying basalt. (iv) Moderate amounts of stone on surface and through the profile. Also lateritic gravels occur. (v) Occurs on benches below Pinelands 2 AMU and is a sedentary Soil developed on basalt with colluvial additions from Pinelands 2 AMU. Pinelands 2

(i) Dull reddish brown, light clay. (ii) Structureless to weak surface but little organic accumulation. (iii) Deep, strongly acid profile; some lateritic gravels throughout. (iv) Generally occurs on ridges, plateaux and upper s'lopes above Pine lands 1 AMU.

Merritts

(i) Brownish black, medium, cracking clay. (ii) Moderate granular surface structure. (iii) Moderately deep soil. (iv) Generally occurs in broad shallow drainage depressions and lower slopes. This is a colluvial soil derived from basaltic and lateritic material. Often occurs below Pechey AMU.

Palmtree

(i) Dark reddish brown, light clay. (ii) Very friable, fine granular surface. (iii) Moderately deep soil. (i v) Subsoil below 60 em has poor permeability. (v) Occurs in most slope positions.

Ravens bourne

(i) Dark reddish brown clay loam to light clay. (ii) Weak fine crumb surface structure. (iii) Deep to very deep soil. Increasing amounts of lateritic gravels with depth. (iv) Occurs in most slope positions, generally east of the Great Dividing Range. 4-12

4.2.8 AI luvium Land Resource Area

Four AMUs occur in the LRA.

(i) Waco (ii) Als (iii) Alw (iv) Alh

(Al = Alluvium; s = st�ongly structured surface;

w = weakly structured surface; h = hard setting surface. )

An abbreviated soil profile description for the Waco together with a soil profile photograph is presented by Cummins and Macnish in Mullins (1978) and a detailed soil profile description is presented by Thompson and Beckmann (1959). An abbreviated soil profile description and the distinguishing features for the other AMUs are presented in this section. Detailed soil profile descriptions are presented in Appendix I.

Distinguishing Features of the AMUs.

Als

(i) Brownish gray, self -mulching, cracking heavy clay. (ii) Strong, fine blocky surface structure. (iii) Deep to very deep soil in valley floors. (i v) Derived from alluvia of predominantly basaltic origin.

Alw

(i) Brownish black, cracking, medium to heavy clay. (ii) Weak, fine crumb surface structure; surface crusting may occur. (iii) Deep to very deep soil in valley floors. (i v) Developed from alluvia of predominantly basal tic and lateritic origin.

A lh

(i) Brownish black, sandy clay loam surface. (ii) Hardsetting massive surface soil. (iii) Texture contrast profile. (iv) Deep to very deep soil in valley floors. (v) Developed on predominantly sandstone alluvia with some basaltic influence. CROWS NEST DISTRICT MAJOR AGRICULTURAL SOILS

BSd (Basalt Scrub deep)

Depth (cm) Description

0 - 25 Brownish black, medium to heavy clay. Weak crumb grading to moderate granular structure. pH 6.5. Clear change to -

25 - 70 Brownish black to dark reddish brown, heavy clay. Moderate, medium blocky structure. pH 8.2. Few calcium carbonate nodules. Diffuse change to -

70 - 110 Greyish brown, heavy clay. pH 9.5 Calcium carbonate nodules. Gradual change to -

120 - 140 Brown, medium clay.

140 + Weathered basalt

BSs (Basalt Scrub shallow)

Depth (cm) Description

0 - 5 Brownish black, clay loam to light clay. Moderate, fine crumb to granular structure. pH 7.0. Occasional small gravels. Clear change to -

5 - 25 Brownish black, light to medium clay. Moderate, medium blocky structure. pH 7.0. Diffuse change to -

25 - 50 + Brown, light to medium clay with large amounts of weathered basalt gravel and some stone. pH 6.8. CROWS NEST DISTRICT MAJOR AGRICULTURAL SOILS

BFs (Basalt Forest shallow)

Depth (cm) Description

0 - 5 Black to brownish black, clay loam or medium clay. Weak, medium granular structure. Small gravels. pH 6.8. Clear change to -

5 - 25 + Brownish black, medium clay. Moderate blocky structure but variable. Large amounts of weathered basalt gravel and stone. pH 7.0.

BFd (Basalt Forest deep)

Depth (cm) Description

0 - 10 Black to brownish black, medium to heavy clay. Strong, medium granular structure. pH 6.8. Clear change to -

10 - 45 Brownish black, heavy clay. Strong, medium to coarse blocky structure. Few calcium carbonate nodules. pH 7.5 - 8.0. Diffuse change to -

45 - 120 Dark brown to brown, medium clay. Blocky structure. Some calcium carbonate nodules. Some basalt gravel. pH 8.5 - 9.0. Diffuse change to -

120 + Weathered basalt with pockets of brown, light to medium clay.

A shallower phase with basalt gravel by 75cm sometimes occurs in mid to upper slope positions.

CROWS NEST DISTRICT MAJOR AGRICULTURAL SOILS

Pechey

Depth (cm) Description

0 - 10 Brownish black to dark reddish brown, loam. Structureless (snuffy). Loose to soft dry consistence. pH 5.5 - 6.8. Gradual change to -

10 - 20 Dark reddish brown, clay loam. Structureless (snuffy). pH 6.5 Clear change to -

20 - 95 Reddish brown, light to medium clay. Fine blocky structure. Ironstone and laterite gravel. pH 6.0. Diffuse change to -

95 + Bright brown to reddish brown, light ot medium clay. Ironstone gravel. pH 6.5. This horizon continues to a depth greater than 300cm.

Palmtree

Depth (cm) Description

0 - 35 Brownish black, light clay. Moderate, fine to medium granular structure. Very friable moist consistence. pH 6.0 - 6.5. Gradual change to -

35 - 65 Dull reddish brown to reddish brown, medium to medium - heavy clay. Moderate, fine to coarse blocky structure. Firm moist consistence. Occasional laterite and basalt gravel. pH 5.5 - 6.5. Diffuse change to -

65 - 120 + Mottled, reddish brown and yellowish brown, medium clay. Coarse blocky to massive structure. Basalt and laterite gravel. Moderately impermeable. pH 5.5 - 6.5. Diffuse change to -

This soil occurs either under eucalypt open forest with a softwood scrub understory or under transitional, eucalyupt forest/rainforest. CROWS NEST DISTRICT MAJOR AGRICULTURAL SOILS

Cabarlah Depth (cm) Description

0 - 5 Reddish brown, loam to clay loam. Weak, fine crumb structure. small amounts of ironstone gravel. pH 6.5. Gradual change to -

5 - 20 Reddish brown, loam to clay loam. Weak, fine granular to fine blocky structure. Moderate amounts of ironstone gravel. pH 6.5. Gradual change to -

20 + Reddish brown, clay loam with occasional pockets of light clay. Moderate to large amounts of ironstone gravel. pH 6.8.

Geham

Depth (cm) Description

0 - 20 Dark brown, light to medium clay. Weak, medium granular structure grading to moderate granular. Small amounts of ironstone nodules and gravel. pH 6.5. Gradual change to -

10 - 40 Brown, light to medium clay. Moderate, fine blocky structure. Small to moderate amounts of ironstone nodules and some basalt gravel. pH 5.5 - 6.5. Clear to diffuse change to -

40 - 90 Mottled, reddish brown or yellowish brown or brown, medium to medium - heavy clay. Strong, blocky structure. Ironstone nodules and some manganese nodules. pH 5.5. Diffuse change to -

90 - 120 + Mottled, brown, yellowish brown and grey, medium to heavy clay. Frequently wet due to a perched water table. pH 5.5. CROWS NEST DISTRICT MAJOR AGRICULTURAL SOILS

Pinelands 1

Depth (cm) Description

0 - 10 Brownish black to dark reddish brown, light clay. Weak to moderate, medium granular structure. pH 6.8. Clear change to -

10 - 40 Reddish brown to dark reddish brown, light to occasionally medium clay. Weak, fine blocky structure. Occasional basalt gravel or basalt floaters. pH 7.0. Diffuse change to -

40 - 80 + Reddish brown, light to medium clay. Increasing amounts of laterite gravel and basalt floaters. pH 7.0.

Note: This soil often occurs in association with Pinelands 2 AMU which has restricted occurrence. Pinelands 1 often occurs on benches fairly high in the landscape and may be a soil partly weathered in basalt with colluvial additions from Pinelands 2 AMU.

Pinelands 2

Depth (cm) Description

0 - 2 Dull reddish brown, light clay. Weak, very fine granular to structureless surface. Little evidence of surface organic matter accumulation. pH 5.0. Clear change to -

2 - 20 Dull reddish brown, light to medium clay. Weak, fine blocky structure. Occasional laterite gravel. pH 4.5 - 5.0. Diffuse change to -

20 - 100 + Dull reddish brown, light to medium clay. Weak, fine blocky structure to massive. Occasional laterite gravel. pH 3.5 - 4.0. This horizon continues to greater depths.

This highly acid soil only occurs on the upper plateau and valleys in the Pinelands area. It occurs in association with Pinelands 1 AMU. It has probably formed on Tertiary sediments and/or tuffaceous material.

CROWS NEST DISTRICT MAJOR AGRICULTURAL SOILS

Als (Alluvium, Alw (Alluvium, structured surface) weakly structured) Depth (cm) Description Depth (cm) Description

0 - 10 Brownish grey, heavy clay. 0 - 20 Brownish black, sandy Strong, fine, blocky structure. clay loam. Massive structure. pH 6.8. Clear change to - Hard dry consistence. Hardsetting. pH 5.8. 10 - 30 Brownish grey, heavy clay. Abrupt change to - Medium, blocky structure. Very firm moist consistance. pH 7.8. Gradual change to - 20 - 30 Dark brown, sandy clay. Coarse blocky structure. 30 - 90 Brownish grey, heavy clay. pH 5.8 - 6.0. Coarse blocky to lenticular Diffuse change to - structure. pH 8.5 - 9.5. Few calcium carbonate nodules 30 - 90 + Dark brown, medium to below 60cm. heavy clay. Coarse blocky Diffuse change to - structure. Hard to very hard dry consistence 90 - 150 Greyish yellow brown, heavy pH 7.8 - 8.0. clay. Firm to friable moist consistence. pH 9.5. Few calcium carbonate nodules. Developed on predominantly sandstone derived alluvium with some basaltic influence. 150 + Contnuing to variable depths and overlying buried material or country rock.

This AMU is self-mulching and cracking. It is developed on alluvia of predominatly basaltic origin.

AlhDepth (Alluvium, (cm) Descriptionhardsetting surface [CMP (TC)] Depth (cm) Description 0 - 10 Brownish black, light ot medium clay. Weak, fine crumb surface structure. surface crusting may occur. pH 6.5. Abrupt change to -

10 - 20 Brownish black, medium to heavy clay. Moderate, fine, blocky structure. Firm moist consistence. pH 7.0. Gradual change to -

20 - 90 Brown, heavy clay. Medium to coarse, blocky structure. pH 8.0 - 9.0. Trace of calcium carbonate nodules below 60cm. Diffuse change to -

90 - 150 + Brown, medium clay. Friable moist consistence. pH 9.0. Few calcium carbonate nodules.

This AMU is cracking. It is developed on alluvia of mixed basaltic and lateritic origin. 5-1

5. LAND USE AND LAND DEGRADATION

5.1 EXISTING LAND USE

Most farmers on the 137 000 ha of rural holdings rely on animal production for their main source of income - dairying, vealer production and cattle breeding and fattening. Only 5% (7 117 ha) of the total area is used for cultivation. The area used for cultivation in each Land Resource Area is indicated in Table 5.1. Of the total area of cultivation, 60 to 70% is used for fodder cropping and the remainder for grain cropping. There is now a tendency to discontinue grain growing on the steep, smaller areas in favour of returning the land to improved pasture. This trend should be encouraged.

In areas with an average annual rainfall of less than 800 mm, winter grazing crops are used to improve dairy production and to a lesser extent for vealer production. Oats is the main fodder crop grown to provide quality feed in winter and spring. There is an increasing interest in the growing of Dolichos lab lab for autumn feeding. Because of the limited area of land suitable for cultivation, oats is often grown on land that because of the high erosion risk is unsuitable for continuous cultivation. With increasing rainfall, the growing of winter grazing crops becomes less important and in the Ravensbourne area with an average annual rainfall of 1 020 mm, farmers rely on a combination of temperate and tropical pastures to provide stock feed at all times of the year.

Of the 130 dairy farmers in the district, 115 supply milk to the Toowoomba and Quinalow factories on a variable percentage of market to manufactured milk. Farmers who supply market milk are more likely to use winter grazing crops than other dairy farmers or graziers to achieve maximum production in winter. In summer the ratio of higher priced market milk to manufactured milk is 3:7, but is reversed in winter. An increase in market milk production in the district is likely to cause an increase in the area used for winter fodder crops and an increase in the use of kikuyu and white clover in sui table areas.

Improve pastures, such as Rhodes grass, Setaria and lucerne provide feed of good quality for fattening cattle and few land use problems occur in these grazing areas providing sound management practices are adhered to.

Approximately 7 200 ha of State Forest and Timber Reserve occur in the District. Forestry is based on logging of stands of native timber including narrow-leaved ironbark, silky oak and hoop pine and plantations of exotic pines in the Pechey area.

Approximately 50 hectares are used for tree crops and small crops. This area is expanding, especially in the Ravensbourne area, for avocados, pecan nuts and kiwi fruit. If irrigation water becomes available an expansion of the horticultural industry could be expected, especially on the Basaltic Red Soils LRA. 5-2

Substantial subdivision of land into 1-5 ha hobby farms has occurred in the Cabarlah and Toowoomba areas. In some cases larger farms have been subdivided into 12 ha farmlets mainly on the Basaltic Red Soils LRA which is good agricultural land.

Perseverance and Cooby Creek Dams and the two National Parks (Craw's Nest Falls and Ravensbourne) provide for recreational land use. A third dam on Cressbrook Creek is currently under construction. Because of its physical attractions and proximity to Brisbane and Toowoomba there is a potential for expansion of recreational land use in the district. If not planned, some of this development could lead to soil erosion.

The quality of underground water varies from good in the Basaltic areas to poor in the Marburg Formation areas. Yields of underground water are low.

There is considerable scope for irrigation using small to medium sized earth dams. It is estimated that 15-20% of the upper catchments of the district have suitable sites for such earth dams with adequate catchment area for irrigation of either improved pastures or tree crops (with trickle irrigation) where soils are suitable.

Total soluble salt levels are high in some creeks in the Marburgs LRA. It is therefore desirable to check salinity levels of the water before constructing an earth dam.

Land use for the district is summarised in Table 5.1.

5.2 LAND DEGRADATION

The following forms of land degradation occur - water erosion (on cultivation and on pasture land), landslip, secondary soil salinity, woody weed regrowth and pasture degradation.

Water erosion occurs both as sheet and gully erosion in cropping and pasture land. Gully erosion mainly occurs on farms with a long history of cropping or in areas with dispersible subsoils. Sheet erosion associated with a long history of cropping has resulted in severe soil losses. It is not uncommon for a 1 metre drop to occur along a fence line. Badly eroded cultivated areas have been removed from cultivation.

The soil erosion situation for the LRAs is summarised in Table 5 .1.

The majority of land currently used for cultivation occurs on steep slopes (Table 5.2) and requires soil conservation measures to reduce soil loss to acceptable levels. TABLE 5. 7 LANV USE ANV SOIL EROSION IN THE CROW'S NEST VISTRICT

AVERAGE ANNUAL LAND RESOURCE LOCATION AND RAINFALL (W-1) AND CURRENT LAND USE SEVERITY OF SOIL EROSION AREA AREA (HA) CLIMATIC ZONE

Basalt West Meringandan 650 - 800 I c Dairying and grazing on Severe sheet and gully erosion (5 000) mostly very small farms occurs on 302 ha of the cultivated ( < 40 ha). Many part area. Minor erosion may occur on time landholders. Small the remaining cultivated land. area of cultivation - 342 ha.

Basalt East Haden/Coalbank 750 - 800 I B Dairying and grazing on Severe sheet erosion occurs on (14 000) small to medium sized 1 613 ha of the cultivated area, farms (100 - 300 ha). Some gul)y erosion also occurs. 9ome graingrowing. Most Minor erosion may occur on the farms have some cultivation, remaining cultivated land. either on steep land slopes or the alluvial flats. Total area Of cultivation is 1 935 ha.

Basaltic Red Highfields 900 I A1 Dairying, piggeries, poultry, Light to moderate sheet erosion Soils (7 000) some horticulture on very occurs on all cultivated areas. small farms ( < 40 ha) . Major area of subdivision with many hobby farms . Total a�ea of cultivation is 914 ha.

Hampton/ 830 - 940 I A1 Dairying and grazing on Moderate erosion occurs on all Craw's Nest small to me·dium sized cultivated areas. Areas of (9 000) properties. Some severe erosion have been cultivation on fairly abandoned. steep slopes. Total area of cultivation is 602 ha. Forestry plantations of exotic pines. TABLE 5.7 {CONTINUEV)

AVERAGE ANNUAL LAND RESOURCE LOCATION AND RAINFALL (MM) AND CURRENT LAND USE SEVERITY OF SOIL EROSION AREA AREA (HA) CLIMATIC ZONE

Basal tic Red Hampton - 900 - 1 200 I A2 Dairying and grazing of All cultivation has slight soil Soils Ravens bourne pasture. Only 260 ha of erosion. (8 000) permanent cultivation. Some areas of temporary cultivation for the establishment of improved pastures. Small areas of avocados.

Blackbutt 1 ooo I A2 Grazing and State Forest. Moderate sheet erosion on all Range Grain and peanut cropping cultivated areas. Some areas (5 000) on 240 ha. of lands lip.

Marburgs Meringandan 760 I c Dairying and grazing on Serious sheet and gully erosion (9 000) very small farms ( < 40 ha). of cultivated areas. Some hobby and part-time farmers. Limited area of cultivation - 423 ha. Forest reserve to protect Cooby Creek Dam.

Coalbank - 800 I B Dairying and grazing on Severe sheet and gully erosion of Crow' s Nest small to medium sized farms cultivated areas. Some minor (18 000) (100 - 300 ha). Grazing on erosion on grazing land. larger properties. About Moderate erosion is occurring on half the total number of areas of abandoned cultivation and farms have some cultivation. in gully lines of soils with Total area of cultivation - dispersible sub soils. 2 235 ha. Some graingrowing. ' <.n <.n on of are areas sub" from areas on lines on and/or pasture EROSION Some runoff Some Some areas SOIL banks especially gully occurs occurs pasture soils. dispersible OF divert on sub flooding. Some areas. areas. eroded, to erosion erosion diversion especially areas. lines are SEVERITY ded erosive landslip. areas dispersible cultivated cultivated soils. higher No waterways Moderate Moderate ero gully require USE area ha. Murphys grazing Some Little ha. the holdings 69 Improved LAND - the 96 Metamorphics (CONTINUED) Limited for - in grain and large Forest. 5.1 extensive slopes. ha). CURRENT of on farms of area. 300 State steep cultivation TABLE > ( grazing crops. cultivation Creek Grazing pastures. Cultivation, largely undeveloped because of Areas of growing and hobby A2 AND I I B ZONE (MM) ANNUAL 200 900 1 - - CLIMATIC AVERAGE 900 800 RAINFALL 300) in (7 AND Creek New and between (HA) as areas bourne Resource other of 000) AREA (15 Occurs Areas. small Land Coalbank England with East LOCATION and association Highway Hampton Murphy's Ravens RESOURCE Granites Marburgs AREA and LAND Granites, Alluvium Metamorphics Metamorphics and 5-6

TABLE 5.2 PERCENTAGE OF TOTAL CULTIVATED LANV ON THE LANV SLOPE CATEGORIES

LAND SLOPE % OF TOTAL CULTIVATED CATEGORY (%) AREA

Valley floors 0 - 1 10 Slopes 1 - 5 14 Slopes 5 - 8 41 Slopes > 8 35

Roadside erosion can be a problem associated with cross road drainage structures. Erosion of table drains is not common. Erosion of disused quarries varies considerably. Most top soil quarries seem to stabilise with woody regrowth and native pasture aft er an initial period of instability. Serious gully erosion occurs in quarries where the sandy top soil of texture contrast soils has been removed. Such a situation exists near Cooby Creek Dam.

Landslip is confined to the vicinity of the eastern excarpment of the Great Dividing Range and to the Blackbutt Range. Landslip generally occurs in prone areas after a 3 to 4 hour period of intense rain during a 2 to 3 day rainfall event. Areas that are particularly prone to landslip include:

(i) Areas where the parent material is underlain by impermeable mudstones (e.g. the Marburg Formation), forming a slip face;

(ii) Areas where the basalts (mostly lateritised) can slide along the cont act zone with the underlying sedimentary or metamorphic rocks (Basaltic Red Soils LRA);

(iii) At gully heads where the soil is most likely to be supersaturated; and

(iv) Where spring outbreaks occur (Holmes, 1981) .

Mass movement 1s generally restricted to slopes > 10% but the lithology and structure of the underlying geology can cause landslip in areas with slopes < 10%.

Secondary salinity has been observed in the 11arburgs LRA but is not a serious problem at this stage.

The district has been used for intensive grazing since settlement in 1850. Due to overgrazing, the better grasses have often been replaced by edible but unproductive grasses like wire grass, love grass, barbed wire grass and ratstail grass. S-7

Lantana is the main woody weed of the district and is most common on the better soils in climatic zones A and B. Heavy infestations occur in the less accessible areas on steep land slopes. Bulldozing and cultivation prior to establishing improved pastures are generally used to control heavy infestations. However, these practices may result in serious soil erosion.

Following clearing of native vegetation, wattles can be a problem on those soils with impermeable subsoils of the Marburgs LRA. Bracken fern and blady grass infest most AMUs in climatic zones Al and A2. Cropping or ploughing prior to sowing improved pasture will normally give temporary control of these two species. Carpet grass or mat grass has recently invaded some pastures on the Basaltic Red Soils LRA near Ravensbourne, and veined verbena is causing some problems on the Basaltic Red Soils LRA between Toowoomba and Geham. Other weeds such as wild turnip and barnyard millet are often associated with fodder crop cultivation.

------�----- ' , .------6-1

6. MANAGEMENT LIMITATIONS AND PRACTICES

FOR AGRICULTURAL PRODUCTION

6.1 INTRODUCTION

The suitability of the AMUs for crop and pasture production and the management requirements for optimum production are defined. The management limitations for agricultural management are listed in Chapter 11 for each AMU. Additional detail on the limitations for the AMUs is available in publications on the "Key Area Studies" for the Land Resource Areas (e.g. Vandersee in Vandersee and Mullins, 1977).

The presence and degree of limitation of the 14 limiting factors of the Land Capability Classification for Agriculture of Rosser et al. (1974) are presented for each AMU in Table 6.1.

6.2 GRAIN AND FODDER CROPS

The major crops commonly grown are grain barley, grazing oats and fodder sorghum.

The suitability of the soils for grain and fodder cropping is presented in Table 6.2.

The shallow stony soils of the Basalt East, Basalt West and Basaltic Red Soils LRAs are unsuitable for cropping due to their shallow soil depth, very low available soil water capacity and the large amounts of stone throughout the profile.

Within the Marburgs, Granites and Metamorphics LRAs, those soils with shallow A horizons over impermeable B horizons are unsuitable for all types of cropping due to the low ·plant available water capacity and low nutrient status. In addition, cultivation of these soils in this climatic environment will lead to exposure of the impermeable, dispersible and highly erodible B horizon. Those soils with a deep surface A horizon over an impermeable B horizon can be used for winter fodder cropping. Those soils with a moderately deep surface A horizon over an impermeable B horizon Cffi\ with careful management be used for winter fodder cropping.

Most of the arable soils of the Marburgs and Metamorphics LRAs will set hard under continuous cultivation or after heavy rain. The soils should be worked when they are in a moist condition to avoid the formation of large clods. On the arable soils of the Marburgs and Metamorphics LRAs, the soils of the Basaltic Red Soils LRA and the weakly structured soils of the Basalts East LRA, tined implements should be used in preference to disc implements to reduce pulverisation of the fragile surface structure.

------··--�.. ------6-2

TABLE 6.1 LANV CAPABILITY CLASSIFICATION FOR AGRICULTURE FOR EACH AMU

LRA/AMU CLASS LIMITATIONS AN D SUBCLASS

Basalt West

Kenmuir VI e4-6 m3 d4-6 r3-5 Purrawunda II-IV e2-4

Basalt East BS s VI-VII e6 m3 d4-6 r4-5 t6-7 BF s VI-VII e6 m3 d4-6 r4-5 t6-7 BS d III-VI e3-6 BF d III-VI e3-6 BF w d III-VI e3-6 m2 p2 dl-2

Basaltic Red Soils Cabarlah V-VI e3-6 m4 n3 d4-6 r3-5 Pechey III-IV e2-4 m2 n2 p2 Palmtree III-VI e3-6 m2 nl-2 Geham III-IV e2-4 m2 n2 p2 Ravensbourne IV-VI e4-6 m2 nl-2 Pinelands 1 and 2 IV-VI e4-6 m2 nl-2 Merritts III-VI e3-6 nl-2

Marburgs/Granites/Metamorphics CSI(TC)MF VI-VII e6d6m4n4k4p4s2-4 FSI (TC)MF VI-VII e6d6m4n4k4p4s2-4 CSI(U)MF VI-VII e6d6m4n4 FSI(U)MF VI-VII e6d6m4n4 CMI(TC)MF IV-VI e4-6 d4 m4 n4 s2-4 CDI (TC)MF III-IV e3-4 m3 n3 CSH (TC)MF IV e3-4 m2 n3 s2 CMH (TC)MF IV e3-4 m2 n3 s2 FMH (TC)MF IV e3-4 m2 n2 s2 p3 CS-MP (TC)MS III-VI e3-6 m2 FS-MP (TC)MS III-VI e3-6 m2 FS-MP (TC)MF III-VI e3-6 m2 CSI (U)Gr VI-VII e6d6m4n4r4-5 t6-7 CMI(U)Gr IV-VI e4-6 m4 n3 t6 d4 CS -MP(TC ) Gr III- IV e3-4 m3 n2 CDP (TC)Gr III-IV e3-4 m3 n2 CSI (TC)M VI-VII e6d6m4n4 t6-7 s2-4 r4-5 CSI(U)M VII-VIII e6d6m4n4 t 7-8 rS CS-MP (TC)H IV-VI e4-6 m2 n2 FS-MP (G)M III-VI e3-6 m2 n2

Alluvium Waco I-II el-2 Al s I-II el-2 Al w II el-2 p2 Al h I II el-2 m2 n2 p2 6-3

TABLE 6.Z SOIL SUITABILITY FOR VRYLANV GRAIN ANV FOVVER CROPPING IN EACH CLIMATIC ZONE

CLIMATIC ZONE LRAs AMUs CROP TYPE A B c

Basalt West, Basalt East. Kemnuir, BPs, BSs, ) All crops ns ns ns Basaltic Red Soils Cabarlah )

Basalt West, Basalt East. All soils except )

Kenmuir, BPs, BSs. ) * winter grain s s s Alluviwn All Soils ) winter fodder s s s Basaltic Red Soils. All soils except ) sununer grain s s s Cabarlah. ) summer fodder s s s Marburgs, Granites, FS-MP (TC and G) ) Metamorphics FMH(TC) )

) winter grain s ls ls Marburgs, Granites, CSH(TC), Q.1H(TC) , ) winter fodder s s s Metamorphics CS-MP(TC), CDI(TC), ) summer grain s ls ls CDP(TC). ) swnmer fodder s s ls

MarbD:rgs, Granites, CMI(TC), CMI(U), ) winter fodder ls ls ls Metamorphics. FMI(TC). ) other crops ns ns ns

Marburg5, Granites, CSI(TC), cs-rcuJ , ) all crops ns ns ns Metamorphics. FSI(TC), CSI(U). )

s suitable

ls � limited suitability ns not suitable

* suited to wheat as well as barley 6-4

The following agronomic management recommendations should be used more extensively:

(i) Fast growing crops with low water requirements such as millet and panicum crops could be used more extensively on soils with low to moderate levels of available soil water. These crops are not suited to the extremely hard setting soils.

(ii) Wheat as well as barley* could be grown on soils of the Basalt East, Basalt West and Alluvium LRAs. Wheat is more suited to thOse soils with a moderate to high nutrient status and plant available water capacity whereas barley can be grown on the poorer soils.

(iii) Winter fodder cropping is undertaken to alleviate winter feed shortages. However additional summer fodder cropping may be warranted to alleviate protein shortages in the autumn period.

(iv) Because of the low nitrogen status of the soils and the high cost of nitrogenous fertilizers, leguminous fodder crops should be used wherever possible. For example:

(a) Woolly pod vetch - similar water requirements to oats but produces less bulk.

(b) Dolichos lab-lab - similar water requirements to forage sorghum.

(c) Cow peas - lower water requirements than forage sorghum. Cow peas are therefore particularly suited to soils of the Basaltic Red Soils, Marburgs, Granites and Metamorphics LRAs.

(v) Undertake opportunity cropping. This practice has considerable potential on the arable soils of the Marburgs LRA. Crops will respond to small falls of rain on these soils.

(vi) A pasture phase should be included in all crop rotations where erosion cannot be adequately controlled with continuous cropping (see Chapter 9).

Generalised fertilizer requirements for six broad groups of AMUs for dryland cropping are presented in Table 6.3.

In groups 2 and 3, phosphorus levels are either marginal or vary considerably. In groups 5 and 6,phosphorus levels can vary from very low to low. In group 6, potassium levels can vary considerably, but generally no response to potassium occurs because of other limiting factors (N, P and moisture). Those soils with loam to clay loam surfaces generally have adequate levels of potassium, while those with sandy surfaces have very low levels of potassium.

* Until recently barley varieties have out yielded wheat. With new wheat varieties, this does not seem to be the case now. I � ""' 0 0 0 0 25 kg/ha 0-25 POTASSIUM OGEN 35 AMUI 30-40 35-60 30-40 30-40 kg/ha 10-30 NITR THE ON CROPS potash. 0 10 superking. kg/ha 0-10 10-20 10-20 0-10 FODDER PHOSPHORUS of AND kg

sulphate of nitram. GRAIN of 50-100 kg FOR or (G) 60 Merritts (TC), or FS-MP (TC) 25-150 kg of CDI AMUs Pinelands, CMH(TC) CDP Geham, or potash (TC), , ), bourne (TC), s BFd Als of superphosphate (TC) wd (U) (TC urea h RECOMMENDATIONS of B F CDI Al Pechey, Raven BSd, CSH CS-MP FS-MP FMH of Purrawunda Palmtree, Waco Alw kg kg muriate of FERTILIZER 110-220 18-110 kg to to 50 Soils Soils 6.3 to Granites Granites, Red Red alent LRA West TABLE equiv burgs equivalent Metamorphics Mar is Metamorphics. equivalent is Marburgs, Marburgs, Basalt East Basalt Basaltic Basalt East Alluvium Alluvium Alluvium Basaltic P N is K kg kg kg P 10-20 10-60 4 3 6 25 5 1 2 GROU • 6-6

Nitrogen requirements depend on the cropping history and soil moisture reserves. Soils in groups 1 and 2 have moderate to high levels of plant available water capacity; those in groups 3,4 and 5 have moderate levels; and those in group 6 have moderate to low levels. Recommended rates of nitrogen have been adjusted to effectively utilise the likely moisture reserves of the soil. Application of nitrogen on soils with a low plant available water capacity, may result in lush vegetative growth, thus depleting soil moisture reserves before crop maturity, particularly if early rain is followed by a dry period. Nitrogen applications are, therefore, safer on grazing crops on the soils of groups 3, 4, 5 and 6 (in Table 6.3). Nitrogen is not essential for fodder legumes but may give a stimulus to early growth. Nitrogen has to be applied through alternate drills of the combine to avoid damage to the legume seed through contact.

In climatic zone A, with a higher rainfall, the higher rates of nitrogen may be used, while in climatic zone C the lower rate should be used. These levels will produce economic returns given favourable seasons.

6.3 HORTICULTURAL CROPS

6.3.1 Smal I Crops

The major small crops grown in the district (including the Toowoomba city area) are lettuce, celery, carrots, cauliflowers, cabbage and broccoli. These crops, apart from carrots, prefer well drained loams and the Ravensbourne, Palmtree and Pechey AMUs of the Basaltic Red Soils LRA are particularly suited. Carrots are mainly grown on the black soils. Most AMUs of the Marburgs LRA are unsuitable because of the hard setting surface and poor subsoil drainage.

These crops are mostly grown in climatic zones Al and A2 where, because of the relatively cool temperatures, summer production can be undertaken.

Expansion of the small crop industry is restricted by the availability of water for irrigation.

6.3.2 Tree and Vine Crops

Avocados and kiwifruit are the main tree crops. Peaches, nectarines, apricots and grapes are also grown.

Avocados, because they can be quickly set back if a large part of their root system is in waterlogged soil for even very short periods, require soils with unimpeded drainage to at least 1.5 m. Some AMUs of the Basaltic Red Soils LRA are therefore most suited. Growers on marginal soils are using a combination of hilling and smaller, precocious varieties, but the life expectancy of the avocados on these soils is only 10 to 12 years. 6-7

Other fruitcrops can be grown successfully on soils with unimpeded drainage to 1 m. Again the most suitable soils are the Ravensbourne, Palmtree and Pechey AMUs of the Basaltic Red Soils LRA and the CDP (TC) in the Granites LRA. Shallower soils (75-100 em) may be used if surface drainage is good, but are not recommended.

6. 4 PASTURES

6.4 0 1 Native Pastures

The predominant native pasture species for the district are pitted blue grass, Queensland blue grass, kangaroo grass and Chloris species. Paspalum has also naturalized in the area. Overgrazing of these pastures is leading to an increase in rat's tail grass, love grass, wire grasses and blady grass.

Pasture growth can be increased by using nitrogenous fertilizers, as shown in a trial near Avenglen (see Appendix XV). However, application of nitrogen fertilizer is unlikely to be economic for most AMUs. The same trial indicated that contour ripping does not increase pasture production. Pasture furrows are also unlikely to be of economic benefit.

6.4.2 Improved Pastures

Pasture improvement is recommended on all soils apart from those with a shallow effective soil depth in the Marburgs, Granites and Metamorphics LRAs (FSI(TC), CSI(TC), FMI(TC), CMI(TC)). The persistence and economics of improved pastures on these soils are doubtful.

In general, Rhodes grass with Siratro is recommended for those soils with a low fertility status and Rhodes grass and green panic with lucerne and Siratro for those soils with a high fertility status. Kikuyu and white clover can be used in climatic zone A, but require high inputs of fertilizer. Codes, which indicate suitable improved pasture specie combinations are listed in Table 6.4 for each AMU in each climatic zone. The improved pasture species within each code are listed in Table 6.5. In addition, suitable improved pasture species for the climatic zones are listed for each AMU in Chapter 11. A summary of the potential of the major pasture species suitable for the district is presented in Appendix XIV.

Fertilizer recommendations for both establishment and maintenance of improved pastures are listed in Table 6.6 (modified from Cull, 1972). 6-8

TABLE 6.4 SUITABLE IMPROVED PASTURE SPECIE COMBINATIONS {BY COVES -SEE TABLE 6.5 FOR INTERPRETATION) FOR THE AMI.l{, IN EACH CLIMATIC ZONE

IMPROVED PASTURE SPECIE COMBINATION FOR TilE CLIMATIC ZONE OF LRA AMU Al A2 B c

Metamorphics CSI(TC) M NR NR NR CSI (U) M NR NR 5 CS-MP (TC) M 1. 3.0 2 .1.0 3.2.0 FS-MP(TC) M 1.3 .1 2 .1.1 3.2.0

Granites CSI(U) Gr NR NR 5 CMI(U) Gr 1.2.0 1.2 .0 4 .1.0 CS-MP(TC) Gr 1.3.0 2.1.0 3.2.0 CDP (TC) Gr 1.3.0 2 .1.0 3.2.0

Marburgs FSI(TC) and CSI(TC) MF NR NR NR NR FSI (U) and CSI(U) MF NR NR 5 5 FMH(TC) MF 1.3.0 2.1.0 3.2.0 4 .1.0 FS-MP(TC) MF 1. 3.1 2.1.1 3.2.0 4.1.0 CMI(TC) MF 1.1.0 1.1.0 4.1.0 4.1.0 CDI(TC) MF 1.3.0 1.3.0 3.6.0 4. 2.0 CSH(TC) MF and CMH (TC) MF 1.3.0 1.3.0 3.6.0 4.2.0 CS-MP(TC) MS 1.3.2 2.1.2 3.2.1 4.2.1 FS-MP (TC) MS 1.3.2 2 .1.2 3.2.1 4.2.1

Basalt West Kenmuir 6.0.0 Purrawunda 6.2.0

Basalt East BSs 3.5.1 BSd 3.5.1 BFs 3.5.1 BFd 3.5.1 BFwd 3.5.0

Basaltic Red Palmtree 1.4.2 2.2.2 3.4.1 Soils Pinelands 1 and 2 1.4 .2 2.2.2 3.4.1 Pechey 1.4 .1 2.2.1 3.4.0 Cabarlah 1.4.1 1.4.1 3.3.0 Geham 1.4.1 1.4.1 3.3.0 Ravens bourne 1.1.2 2.1.2 3.1.1 Merritts 1.4.1 2.2.1 3.4.0

Alluvium Waco 6.2.1 6.2.0 6.2 .0. Als 6.1.1 6 .1.0 Alw 6.1.1 6 .1.0 Alh 6 .1.0 6.1.2

NR not recommended for improved pastures

= soil does not occur in the climatic zone 6-9

TABLE 6.5 IMPROVED PASTURE SPECIES FOR THE COVES IN TABLE 6.4

SPECIES FOR 1st Digit 2nd Digit 3rd Digit

1. Rhodes grass, 1-medics (but only if 0 - paspalum soil pH> 6.5) 1-kikuyu (if N 2-medics (but only if is applied) soil pH> 6.5), white 2-kikuyu, green clover panic 3-medics (but only if soil pH> 6.5}, white clover, fescue, phalaris 4-white clover, fescue phalaris

2. Rhodes grass, 1-medics (but only if 0 - paspalum, soil pH> 6.5), fescue, 1-kikuyu (if N lucerne phalaris, white clover is applied) 2-fescue, phalaris, 2-kikuyu, green white clover panic

3. Rhodes grass, 1-medics (but only if 0 - paspalum, soil pH> 6.5} 1-green panic creeping blue 2-medics (but only if grass, Siratro, soil pH> 6.5), lucerne, Kazungula white clover Setaria 3-whi te clover 4-white clever, lucerne 5-white, clover, lucerne, medics 6-medics (but only if soil pH> 6.5}, lucerne

4. Rhodes grass, 1-medics (but only if 0 - creeping blue soil pH > 6. 5) 1-green panic grass, 2-medics (but only if Siratro soil pH> 6.5), lucerne

5. Siratro and/or creeping blue grass

6. Rhodes grass, 0 - 0 - green panic, 1-white clover, paspalum 1-kikuyu medics, lucerne, 2-Makarikari grass 2-Siratro creeping blue (cv. Bambatsi), grass Columbus grass

EXAMPLE: 1.2.1 is Rhodes grass, paspalum, medics (but only if the soil pH> 6.5} and kikuyu (if N is applied} . ' G "-' "' at s ? 0-20 0-20 ns 0-10 ns 10-20 10-20 10-20 10-20 when ? ? X X ? X X ns ns recommended required is p K ? MAINTENANCE 0-10 0-10 ns ns 0-10 kg/ha 10-20 10-20 it 10-20 10-20 only pastures. where - N ? sown ns 0-25 ns 0-25 15-35 15-25 10-25 15-25 generally for those used. IMPROVEV in are are ? ? ? S No FOR No Lime Yes No Yes ns Pellet even suitable and not Mo legumes - ? ? VATIONS Mo* Yes ns ns Yes Yes ns Yes Yes sites, VISTRICT * ns some

NEST ? S* 40 0-40 RECOMMEN 40 0-40 20-60 on 20-40 OW'S ? ? ? X X K - CR X X X ns ns ns ns ESTABLISHMENT question THE FERTILIZER

a IN ? p 0-20 ns 0-20 ns -- 40-60 kg/ha 40-60 20-60 20-40 10-40 also is cultivation. PASTURES N ? GENERALISEV ns ns 0-35 0-25 10-25 10-35 10-25 10-25 old on 6.6 medic seed of TABLE recorded Cabarlah, Merritts soils bourne, FSI, unknown·. FMI CMI AMUs soils soils bee�1 pelleting ·recorded. are soils Pinelands Pechey, Geham, Palmtree Other Other CSI, Ravens All csi; All Ms(scrub) CMI, not have lime Red for East West tic requirements responses responses need LRA The present. ? Granites Basalt X Soils Marburgs and Basal Basalt Metamorphics 6-11

6.4.3 Pasture Management

Grazing management should not only aim at maximum animal production but should also prevent pasture and soil degradation.

(i) Grazing Management

Recommended carrying capacities for both native and improved pastures to maintain an adequate ground cover are presented in Table 6.7. Stocking rates should be flexible to allow for adjustment according to the season. The Metamorphic soils mostly occur on steep land slopes and are generally not suited for development.

Sown pastures require spelling during summer. An ungrazed period of 2-4 months, at least once in every 4 years will improve pasture persistence (Scattini, pers. comm. ). Pastures on eroded land should be rested every third growing season.

On unstable soils, such as CSI (TC) and FSI(TC) , pastures should be grazed after rain and then destocked. Browse species and quick maturing ephemerals can be utilised after rain. If pastures on these soils are continuously grazed, gully lines which produce better feed will be preferred by stock and will become unstable. Serious gully erosion will result. The overgrazing of gully lines together with the location of watering points in the gully are thought to be the main causes of gully erosion in pastures on these soils.

(ii) Burning Strategy

Regular burning (usually in August) of pastures on grazing properties in the eastern half of the district is carried out. Burning of pastures on dairy farms is not common.

Burning to remove rank grass every two to three years should be sufficient. It is best carried out soon after rain in spring to allow the grass to grow and provide protection against storms in summer. Burning after rain gives a fire of low intensity, which leaves some litter on the ground. Attempts to control lantana with burning have not been successful.

Areas that are particularly prone to soil erosion, such as areas with CSI(TC) and FSI(TC) soils should not be burned except under the most favourable conditions.

When burning off, fire breaks should be constructed to prevent the fire reaching areas that should not be burned, such as areas on steep land slopes with erodible soils.

The use of urea and molasses licks allows the better use of old or rank, low quality pasture and could reduce the need to burn. 6-12

TABLE 6. 7 RECOMMENDED CARRYING CAPACITIES FOR THE SOILS OF THE LANV RESOURCE AREAS

CLIMATIC RECOMMENDED SOIL GROUP PASTURE TYPE ZONE CARRYING CAPACITY ha/beast

Al Basaltic Red Soils 1* Improved pasture 0.7 2** Improved pasture and fertilizer 0.7 Native pasture 1. 1 Marburgs 1+ Native pasture/timber 4 - 6

Basal tic Red Soils 1 Improved pasture 0.9 2 Improved pasture and fertilizer 0.9 Native pasture 1.8 Marburgs 1 Native pasture/timber 4 - 6

B Basaltic Red Soils 1 Improved pasture 1. 1 2 Improved pasture and fertilizer 1. 2 Native pasture 2. 4 Basalt East Improved pasture 1. 2 - 1. 6 Native pasture 2.0 - 2. 4 Mar burgs 1 Native pasture/timber 5 - 7 2++ Improved pasture 1.2 - 1.8 Native pasture 2.4 - 3.6 Granites Improved pasture 1.6 Native pasture 2.4 Metamorphics Native pasture/timber 5 - 9

c Basalt West Native pasture 2. 4 Marburgs 1 Native pasture/timber 5 - 7 2 Improved pasture 1.4 - 2.0 Native pasture 2.4 - 3.6

* Basaltic Red Soils 1 are the scrub soils - Ravensbourne, Pinelands. ** Basaltic Red Soils 2 are the forest soils - Merritts, Geham, Cabarlah, Pechey, Palmtree.

+ Marburgs 1 are the shallow Marburgs - FSI(TC) , CSI (TC) , FSI (U) and CSI(U) .

++ Marburgs 2 are the deeper Marburgs.

The soils of the Granites LRA have not been separated into groups. In most cases shallow and deep soils will occur on the same property. 6-13

(iii) Stock Watering Points

Stock watering points should be carefully selected to avoid stock tracks concentrating runoff water and causing soil erosion.

Watering points should, therefore, be selected on low sloping areas and water from waterholes or dams should be pumped to troughs on the adjacent flat areas. This is particularly important where waterholes are situated in gullies with steep side slopes or on soils with unstable subsoils (FSI (TC), CSI (TC) , FeU (TC), CMI (TC)).

(iv) Fencing

Paddock size should allow control of stock and implementation of a grazing system. Gates should be located as much as possible on flat ground, away from drainage lines.

(v) Laneways

Laneways on dairy farms are often badly eroded. Reclamation is generally not practical. Whoa-boys or check banks* discharging into contour banks or pasture land are recommended.

* Whoa-boys or check banks a small diversion drain across a roadway. 7-1

7. SPECIFICATIONS FOR RUNOFF CONTROL STRUCTURES

7.1 INTRODUCTION

In most sloping situations in the Crow•s Nest District, runoff control structures will be required to intercept runoff water before it can concentrate and reach scouring velocities. The design principles for runoff control structures are described in Part 9 of the Queensland Soil Conservation Handbook. Only the actual specifications, the reasoning for these specifications, the construction techniques and maintenance requirements for structures in the Grow's Nest District are listed in this technical manual.

7.2 RUNOFF ESTIMATION

The Rational Method is used to estimate surface runoff. In the Grow's Nest District it provides satisfactory results with the following exceptions:

(i) Diversion banks carrying runoff from grassland are overdesigned. In this cas� the runoff coefficient for grassland may be overestimated.

(ii) Waterways in large catchments may be overdesigned. This is possibly because the design storm only occurs in parts of the catchment.

Runoff coefficients for use in the Rational Method vary with the soil, land use, landform and rainfall intensity. The AMUs of the district have been grouped into three runoff coefficient soil categories - A to C (see Table 7. 2.1). Category A are those soils with high rates of infiltration under saturated conditions and category G are those soils with low infiltration rates under saturated conditions. Runoff coefficients for a range of land uses and land forms for the soil categories are presented in Table 7.2. 2.

To facilitate runoff estimates for waterway and diversion bank design, the time of concentration for a range of cover conditions and land slopes and in addition the rainfall intensity for the 1 in 10 design frequency (for use in the Rational Method) are presented in Appendix IV.

Runoff to be catered for at the contour bank outlet would be expected to depend on land slope, bank spacing (standard or double standard), channel velocity, drainage design rating* and bank length. Peak runoff for these variables is presented for a runoff coefficient of 0.5 for the 1 in 10 design frequency in Appendix V. It is apparent from the values that channel velocity and drainage rating do not significantly influence runoff and that slopes > 2% behave similarly.

* Drainage Design Rating see Section 7.4. 3. 7-2

TABLE 7.2.7 RUNOFF COEFFICIENT SOIL CATEGORIES

FOR THE AMUI

RUNOFF COEFFICIENT LRA AMU SOIL CATEGORY

Basalt West Kenmuir B* Purrawunda B

Basalt East BSs B BFs B BSd B BFd B BFwd B

Basal tic Red Soils Cabarlah B Pechey B * Palmtree A Geham B Ravens bourne A Pinelands 1 and 2 A Merritts B * Marburgs CSI (TC) MF c FSI (TC) MF c CSI (U) MF c FSI (U) MF c CMI (TC) MF c CDI (TC) MF B CSH (TC) MF B CMH (TC) MF B FMH (TC) MF c CS-MP (TC) MS B FS-MP (TC) MF B FS-MP (TC) MS B

Granites CSI (U) Gr c CMI (U) Gr B CS-MP (TC) Gr B CDP (TC) Gr A

Metamorphics CSI (TC) M c CST (U) M c CS-MP (TC) M B FS-MP (G) M A

Alluvium Waco B Al s B Al w B Al h B

c � * A � permeable soil; B � medium; impermeable soil. 7-3

TABLE 7.2.2 RUNOFF CO-EFFICIENTS FOR A RANGE OF LANV USES ANV LANVFORMS FOR THE RUNOFF CO-EFFICIENT SOIL CATEGORIES

RUNOFF CO-EFFICIENT RUNOFF CO-EFFICIENT FOR SOIL CATEGORY A DESIGN FREQUENCY OF LAND USE LANDFORM (Table 7.2.1) 1:10 1:100

A Timber/Pasture Rolling < 10% 0.1 0.2 (permeable soil) Hilly > 10% 0.1 0.2

Cultivation Rolling < 10% 0.3 0.4

Hilly > 10% 0.4 0.6

B Timber /Pasture Rolling < 10% 0.2 0.3 (medium) Hilly > 10% 0.3 0.4

Cultivation Rolling < 10% 0.5 0.7

Hilly > 10% 0.6 0.7

c Timber/Pasture Rolling < 10% 0.3 0.5 (impermeable soil) Hilly > 10% 0.5 0.7

Cultivation Rolling < 10% 0.6 0.8

Hilly > 10% 0.7 0.9

------··---·------· 7-4

7.3 THE RUNOFF CONTROL STRUCTURES

In the Crow's Nest District the major structures used for runoff control are listed below. In general these structures are only used in cropped situations on grain and fodder crops, small crops, row crops, and tree and vine crops. They are generally not considered economic in pasture land except in crop/pasture rotations or for the rehabilitation of eroded pasture land.

The major structures/measures used are:

(i) Contour banks for grain cropping areas, row crops and in some cases small crops.

(ii) Modified contour banks/beds for small crops. Normal contour banks may be used for small crops.

(iii) Diversion banks and pondage banks.

(iv) Spreader channels to spread concentrated water flow in grassland.

(v) Waterways.

(vi) Other measures such as grass strips, contour ripping and pasture furrows. 7-5

7.4 SPECIFICATIONS FOR CONTOUR BANKS

Contour banks are used predominantly in grain and fodder cropping areas. Summary specification; for contour banks are presented in Table 7. 4.1 - summary sheets l and 2.

7.4. 1 Suitability of Soi Is and Sites for Contour Bank Construction

Contour banks should not be constructed on:

(i) Those texture contrast soils with both impermeable subsoils and with shallow to moderately deep A horizons - FSI(TC), CSI(TC), FMI(TC) and CMI(TC). Construction of contour banks on these soils will lead to exposure of the impermeable, dispersible and highly erodible B horizon. Exposure of this B horizon will lead to tunnel erosion and gullying. If it is absolutely necessary, banks may be constructed from the bottom side on FMI(TC) and CMI(TC).

or (ii) Those shallow to moderately deep, uniform soils overlying rock - CSI(U), FSI(U), CMI(U), FMI(U), Kenmuir, BSs, BFs and Cabarlah. The shallow soil depth does not provide sufficient soil for contour bank construction.

or (iii) In areas where stable contour bank outlets into a creek or drainage line are not available. This is mostly a problem on texture contrast soils e.g. FMH(TC)MF. This problem can be overcome by constructing a waterway with a safe outlet in a downstream position, parallel to the creek or drainage line.

or (i v) On very steep slopes - > 15%.

7.4.2 Contour Bank Type

(i) Broad base cultivated contour banks or broad base top side contour banks are recommended for land slopes up to 6% on those soils that may crack sufficiently to cause contour bank failure. Such soils include the (a) Purrawunda and (b) Waco. Broad base grassed contour banks are recommended on the Purrawunda if slopes exceed 6%. This is because channel capacity is difficult to achieve and the construction costs per hectare, due to the close spacings on steep land slopes, are prohibitive for broad base cultivated banks above 6% land slope. 7-6

TABLE 7.4.1 SUMMARY SPECIFICATIONS FOR CONTOUR BANKS SHEET

l1INIMUM DRAINAGE MAXIMUM SOIL SPECIFICATIONS DESIGN PERMISSIBLE LRA AMU SUITABILITY .FOR TYPE RATING VELOCITY (m/sec)

Basalt West Kenmuir ns 7.4

Purrawunda s BBTS 6.8 0.5

Basalt East BSs ns NB 7.4 0.5

BPs s NB 7.4 0.5

BSd s NB 6.8 0.5

BPd s NB 6.8 0.5

BPwd s NB 6.8 0.5

Basal tic Red Cabarlah ns NB 8.0 0.6

Soils Pechey s NB 8.0 0.6

Palmtree s NB 8.0 0.6

Geham s NB 8.0 0.5

Ravens bourne s NB 8.6 0.6

Pinelands 1 and 2 s NB 8.6 0.6

Merritts s NB 6.8 0.5

Mar burgs CSI (TC) MF ns 6.2 0.5

PSI (TC) MF ns 6.2 0.5

CSI (U) MF ns 6.8 0.5

PSI (U) MP ns 6.8 0.5

CMI (TC) MP ls NB 6.8 0.5

cor (TC) MP s NB 6.8 0.5

CSH (TC) MF s NB 6.8 0.5

CMH (TC) MP s NB 6.8 0.5

PMH (TC) MF s NB 6.2 0.5

CS-MP (TC) MS s NB 7.4 0.5

FS-MP (TC) MF s NB 7.4 0.5

FS-MP (TC) MS s NB 7.4 0.5

6.8 0.5 Granites CSI (U) Gr ns 7.4 0.5 CMI (U) Gr ls NB

CS-MP (TC) Gr s NB 7.4 0.5 0.5 COP (TC) Gr s NB 8.6

6.2 0.5 Metamorphic s CSI (TC) M ns 0.5 CSI (U) M ns 6.8

CS-MP (TC) M s NB 7.4 O:S 0.6 FS-MP (G) M s NB 8.0

0.5 Alluvi urn Waco s BBTS 0.5 Al s s NB 0.5 AI w s NB

Al h s NB 0.5

·------· 7-7

TABLE 7.4.1 SUMMARY SPECIFICATIONS FOR

CONTOUR BANKS - SHEET Z

(i) Contour Bank Spacing

(a) Standard spacing VI = 0.15 (s + x) *

(b) Double standard spacing VI = 0. 3 (s + x) *

* for land slopes of 2 to 7%.

(ii) Constructed Bank Height

H=d+f+s equation 7. 3

d = design depth of flow - see Appendix VI

f = freeboard 0 .15 m s = settlement (%of (d +f) depending on the AMU).

(iii) Bank Length

Normal maximum bank length up to 600 m. Banks up to l 200 m can be used provided gradients are reduced and bank heights increased.

(iv) Design Frequency - 1 in 10.

(v) Maintenance

Remove silt from channels to maintain bank design capacity. 7-8

(ii) Narrow base banks are adequate on all other soils suitable for contour bank construction. BF d, BSd and Merritts AMUs crack to a certain extent but most of these soils occur on steep land slopes ( > 6%) and narrow base banks appear adequate.

7.4. 3 Contour Bank Spacing

Contour banks are spaced at:

(i) Standard spacing (ss) which is determined by VI � 0. 15 (s + x) ...... equation 7.1

and (ii) Double standard spacing (ds) which is determined by VI � 0. 3 (s + x) ...... equation 7.2 where VI � vertical interval (m) between contour banks.

s � land slope (%) x � drainage design rating which is tabulated for each AMU in Table 7.4. 2.

Standard spacing will prevent rilling under bare fallow conditions with stubble removed for the 1 in 10 year storm. Double standard spacing will prevent rilling under bare fallow conditions with stubble retained for the 1 in 10 year storm.

This method should not be used to determine the vertical interval for steep or low land slopes.

On steep* land slopes the horizontal distance is determined as follows:

(i) For land slopes of 7 - 10% a horizontal distance of 31 m is used for all soils.

(ii) For land slopes of 10 - 12% a horizontal distance of 31 m is used for soils with a drainage design rating> 7.0 and 24 m for soils with a drainage design rating < 7.0.

(iii) For land slopes greater than 12% a horizontal distance of 24 m is used for all soils.

For land slopes < 2% a standard horizontal distance of 120 m is used.

Bank spacing may have to be varied to suit the availability of stable contour bank outlets. This is especially a problem on texture contrast soils with outlets into creeks that have steep side slopes. Double standard spacing should not be exceeded if bank spacing is varied for this reason. If stable outlets at suitable spacings are not available, an auxillary waterway parallel to the main watercourse will be required.

Standard spacing should not be exceeded for parallel banks as some sections have higher than acceptable gradients.

* Land slope is extremely variable in steep areas and the estimated steepest land slope for an area is used to derive the horizontal distance. 7-9

TABLE 7.4.Z VRAINAGE VESIGN RATINGS FOR THE AMU\

DRAINAGE DESIGN LRA AMU RATING

Basalt West Kenmuir 7.4 Purrawunda 6. 8

Basalt East BSs 7.4 BFs 7.4 BSd 6.8 BFd 6.8 BFwd 6.8

Basaltic Red Soils Cabarlah 8.0 Pechey 8.0 Palmtree 8.0 Geham 8.0 Ravensb ourne 8.6 Pinelands 1 and 2 8.6 Merritts 6.8

Marburgs CSI (TC) MF 6.2 FSI (TC) MF 6.2 CSI (U) MF 6.8 FSI (U) MF 6. 8 CMI (TC) MF 6.8 CDI (TC) MF 6.8 CSH (TC) MF 6.8 CMH (TC) MF 6.8 FMH (TC) MF 6.2 CS-MP (TC) MS 7.4 FS-MP (TC) MF 7.4 FS-MP (TC) MS 7.4

Granites CSI (U) Gr 6.8 CMI (U) Gr 7.4 CS-MP (TC) Gr 7.4 COP (TC) Gr 8.6

Metamorphics CSI (TC) M 6.2 CSI (U) M 6. 8 CS-MF (TC) M 7.4 FS-MP (G) M 8.0

Alluvium Waco NA Al s NA Al w NA Al h NA

NA � Not Applicable - These soils occur on slopes < 2% for which a standard horizontal distance of 12 0 m is used. 7-10

7.4.4 Maximum Permissible Channel Velocity

Maximum permissible bare channel velocities for contour banks are presented in Table 7.4.3.

TABLE 7.4.3 MAXIMUM PERMISSIBLE VELOCITIES

FOR BARE EARTH CONTOUR BANK CHANNELS

MAXIMUM PERMISSIBLE AMUs VELOCITY m/sec

Merritts, Geham and AMUs of the 0. so Basalt West, Basalt East, Granites, Metamorphics and Marburgs LRAs with the exception of FS-MP(G) .

FS-MP(G) and AMUs of the Basaltic 0.60 Red Soils LRA with the exception of Merritts and Geham.

7.4.5 Channel Gradient

(a) Graded Bo:riks - narrOZJ base contour banks

Maximum channel gradients that should not be exceeded are indicated in Appendix VI.

Variable gradients starting with 0.1% and finishing with 0.3% are recommended for land slopes < 7%. On land slopes of < 2%, a maximum gradient of 0.2% may be used, as it is desirable to keep the channel gradient to < 10% of the land slope. On land slopes > 7%, a constant channel gradient of 0.4% is used for bank lengths < 300 m and of 0.3% for bank lengths > 300 m. The constant and steeper channel gradients are used on steep land slopes for the following reasons:

(i) Distance between survey points on steep land slopes is reduced from 30 to 15 m to prevent the occurrence of irregularities. There is less error in surveying steeper channel gradients over this shorter distance.

(ii) During construction, irregularities in the channel are more likely to occur with low channel gradients. This is not a problem on land slopes < 7%. Where a contour bank crosses a depression line (natural or eroded), the channel gradient �ay be increased to a maximum of 1.5%. This is done because:

(i) Contour banks are taken directly across depression lines to avoid very sharp curves.

(ii) Construction of a contour bank across a depression line will require extra soil which will lead to a deeper excavation in the channel. Increasing the channel gradient will prevent ponding in this area. 7-11

(b) LeveL B a:nks

Level banks may be used on permeable soils (runoff co-efficient category A only) when runoff retention is required by the landholder. Wetness is a problem in the channel and level banks are only generally recommended in pasture land.

For parallel banks, channel gradient will vary from level to very steep. Desirable maximum gradient depends on the permissible runoff velocity in the channel, which in turn is governed by the AMU . Parallel layouts have been used for row crops such as potatoes and onions where machinery requirments demand it.

(d) Outlet Gradients

Channel gradients used in the outlet area of contour banks vary:

(i) If the bottom of the contour bank channel is lower than the outlet area and the outlet area is or will be grassed, the bank is turned down sharply in the last 3 m, giving the channel an outlet gradient of approximately 60% of the land slope.

(ii) If the outlet area is lower than the channel or if the channel will be cultivated right up to the outlet area, the outlet gradient should not exceed the maximum gradient of the bank.

7. 4.6 Depth of Flow - Narrow Base Contour Banks

The design depth of flow in contour banks is influenced by:

(i) Estimated peak runoff between banks.

(ii) Channel gradient which is governed by maximum permissible velocity.

(iii) Cross sectional area which is governed by land slope and

(iv) Channel shape. Field checking of the shape of contour banks 5 years after construction showed most banks to have a triangular shape. Depth of flow in this manual is based on a triangular cross section.

The design depth of flow for the 1 in 10 storm based on these variables and a triangular shape are presented for narrow base contour banks in Appendix VI. In addition the channel velocity and peak runoff is presented for the dep th of flow. 7-12

7.4. 7 Constructed Bank Height

Constructed bank height is determined from the equation

H � d + f + s ...... equation 7.3

where H � constructed bank height (m) before settlement d � design depth of flow (m)

� f freeboard - 0. 15 m s allowance for settlement.

Design depth of flow for narrow base contour banks is shown in Appendix VI.

Freeboard is added to compensate for:

(i) Irregularities occurring during construction of the bank.

(ii) Build-up of runoff (standing wave) at sharp curves in the bank.

(iii) Hydraulic pressure occurring on the narrow top section of the bank.

The addition of 0.15 m of freeboard to the depth of flow will increase the design frequency and the design velocity.

Settlement (% of d + f) depends on the construction technique and AMU . Settlement values are presented in Table 7. 4. 4.

TABLE 7.4.4 SETTLEMENT VALUES (%] FOR CONTOUR BANKS

DOZER GRADER CONSTRUCTION CONSTRUCTION

Cracking Soils 30 25 Non Cracking Soils 25 20

7.4.8 Contour Bank Length

Bank length normally does not exceed 800 m. To facilitate farm management it is sometimes desirable to construct longer banks. The design depth of flow for bank lengths up to 1 200 m is provided in Appendix VI.

Banks longer than 1 ZOO m must be individually designed and will require low channel gradients to keep the velocity of the increased flow from the larger catchment between the banks within permissible limits. Longer banks will result in higher banks which become expensive to construct. 7-13

7.4.9 Contour Bank Failure/Design Frequency

Bank capacity is designed for the 1 in 10 return period. However by adding O.lSm of freeboard to the design depth of flow, the actual return period may exceed 1 in 100. For this higher return period, channel velocity will exceed the maximum permissible velocity. This higher velocity, which occurs only occasionally has been observed not to cause permanent damage to the channel.

In practice, bank failure occurs more frequently than the 1 in 100 return period for two possible reasons:

(i) Interbank erosion deposits silt in the channel, thus reducing its capacity.

(ii) Waterways or natural depressions for the 1 in 10 or 1 in SO design frequency may not be able to handle the 1 in 100 flow, thus causing the runoff to back up, overtop and break contour banks.

Contour banks performed much better than expected during the high intensity rainfall events of February, 1981 in the district. This was probably due to the generally short length of the contour bank, the use of standard spacing and the channel gradient of 0.4% used on the steep land slopes. Some banks failed at the outlet, because the natural depressions could not handle the neak flow.

7.4.10 Contour Bank Construction

Contour banks should not be constructed until waterways are properly grassed up. Recommended construction techniques are explained in an advisory leaflet by Lehmann and Bartels (1978a).

Dozer blades and grader blades have both been used successfully for the construction of contour banks. Generally, a dozer blade is preferred for contour banks.

It may sometimes be necessary to construct contour banks on soils considered not suitable for bank construction (see Section 7.4.1) (e.g. a diversion bank to divert runoff from an eroding gully). This requires the following special construction techniques (Roberts pers. comm.).

The topsoil is pushed uphill first and the bank constructed with the subsoil. After construction of the bank, the topsoil is pushed back into the channel and onto the front slope of the bank. Ideally, the bank should be compacted as much as possible during construction to prevent dispersion. A grader built bank will compact better than a dozer built bank. This construction method is expensive and cannot be recommended for soils suited to normal construction. There is also a higher than normal risk of failure of banks on these unsuitable soils. 7-14

7. 4. 11 Contour Bank Maintenance

Interbank erosion will deposit silt in the channel and reduce its capacity. Channel capacity of contour banks can be maintained by:

(i) Reducing interbank erosion with stubble mulching and other cultural practices.

(ii) Periodic removal (at 5 - 10 year intervals) of silt from the channel. Broad base contour banks require more frequent maintenance, because

-- _:tluo__cons:tant_culthcation_Q£ t_ae__ bank reduces __i ts capacity. 7- 15

7.5 SPECIFICATIONS FOR MODIFIED CONTOUR BANKS/BEDS FOR SMALL CROPS

In most situations modified contour banks/beds on the straight and para11e1 may be used for small crops to facilitate farming operations such as irrigating and spraying. These structures are basically contour banks/beds or ditches with grassed channels and with access tracks which link up with the farm roads. A typical soil conservation layout for a small crop farm using modified contour banks/beds is shown in Figure 7.1.

Normal contour banks (both graded and parallel) may be used for small crops but do have disadvantages associated with some farm operations. Summary specifications for modified contour banks/ beds are presented in Table 7.5. 1 - summary sheets 1 and 2.

7. 5. 1 Suitabi I ity of Soi Is

Those soils that are suitable for the construction of normal contour banks are suitable for modified contour banks/beds (Section 7.4.1).

7.5. 2 Modified Contour Bank/Bed Type

Four types are used (Figure 7.2).

(i) The beds are built up in the middle as shown in the cross section in Figure 7.2. This type is only suitable on land slopes less than 2%. On steeper slopes the spacing between channe1s (bed width) has to be reduced as excessive earth movement will be required to form a bank that is high enough.

(ii) Parallel and straight contour banks with vehicle tracks located in the channel as shown in Figure 7.2. This type is suitable for all land slopes but is not suited to very steep channel gradients.

(iii) Parallel and straight contour banks with vehicle tracks located on the bottom side of the bank (see Figure 7.2). This type is suitable for most land slopes and channel gradients.

(iv) Parallel sub surface ditches are used instead of banks with vehicle tracks stradling the ditch as shown in Figure 7.2. Sub surface ditches are recommended for poorly drained sites or soils but have not been fully tested as yet in the district. 7-16

FIGURE 7.1 TYPICAL SOIL CONSERVATION LAYOUT

FOR A SMALL CROP FARM

' - t - t Tr "'" � + + + + r- + + + + ,...,..,• ��J 1- ' ,� Land �[ Slope 1- �; -J- I I " B I � I

r �� I - " 1- I I � l I I I t --..::::..__- - I ------..!- "'-- I -..; _ __ _ --

....t'"t"-t .._ ...... - ..... �c,�·_

DIVERSION BANK ...... "i'r."'"'"'"'"""' INVERT IN WATERWAY .. * BANK or DRAIN COMBINED MAIN ACCESS ROAD . .. WITH FEEDER TRACK .. UNDER GROUND MAIN .. I I 1.-1 I I WATERWAYS...... n. IRRIGATION LINE ..

A Major natural depression BUILDING • dovolopod as w.t.rw"' CATCHMENT RUNOFF.. ' ' ' B Small depression developed as waterway that can be crossed with implements 7-17

TABLE 7. 5.1 SUMMARY SPECIFICATIONS FOR

MOVIFIEV CONTOUR BANKS/BEVS - SHEET 1

MAXIMUM SOIL PERMISSIBLE LRA AMU SUITABILITY VELOCITY ROW FURROWS (m/sec)

Basalt West Kenmuir ns Purrawunda s 0.5

Basalt East BSs ns 0.5 BFs s 0.5 BSd s 0.5 BFd s 0. 5 BFwd s 0.5

Basaltic Red Soils Cabarlah ns Pechey s 0.6 Palmtree s 0.6 Geham s 0.6 Ravensbourne s 0.6 Pinelands 1 and 2 s 0. 6 Merritts s 0.5

Marburgs CSI (TC) MF ns FSI (TC) MF ns CSI (U) MF ns FSI (U) MF ns CMI (TC) MF ls 0.5 CDI (TC) MF s 0.5 CSH (TC) MF s 0.5 CMH (TC) MF s 0. 5 FMH (TC) MF s 0.5 CS-MP (TC) MS s 0.5 FS-MP (TC) MF s 0.5 FS-MP (TC) MS s 0.5

Granite s CSI (U) Gr ns CMI (U) Gr ls 0. 5 CS-MP (TC) Gr s 0.5 CDP (TC) Gr s 0.5

Metamorphics CSI (TC) M ns CSI (U) M ns CS-MP (TC) M s 0.5 FS-MP (G) M s 0.5

Alluvium Waco 5 0.5 Al s s 0.5 Al w s 0.5 Al h s 0.5

s ; suitable; ls ; less suitable; ns ; not suitable.

rnmr------7-18

TABLE 7.5.1 SUMMARY SPECIFICATIONS FOR

MOVIFIEV CONTOUR BANKS/BEVS - SHEET 2

(i) Spacing

Double standard spacing is recommended VI ; 0.3 (s + x) equation 7.2

(ii) Constructed Bed Height

equation 7.3

d ; design depth of flow - see Appendix VII s;settlement (% of d depending on AMU).

(iii) Design Frequency

1 in 10.

"�------·---�-- .------7-19

TYPES TOUR BANK/BfV MOVIFIEV CON f!GURf 1.t CROP AREAS FOR SMALL

cultivated area channel

--�------

------�-- -�------Type 1

bank

cultivated area

------

TY1.Je 2

cultivated area T d

--- � ------

track cultivated area cultivated area

Type 4

of floW d � depth l th 6f channe w � wid channel above the ht of bed h � heig 7- 20

7.5.3 Modified Contour Bank/Bed Spacing

Standard spacing is recowNended for those crops requiring a very fine seedbed. Doubl.e standard spacing is adequate for all other crops as the furrows between the hilled crop rows will carry much of the runoff water and the bare fallow period between crops is generally minimal. Distance between banks has to be adjusted to suit multiples of the bed width.

7. 5.4 Maximum Permissible Channel Velocity

Maximum permissible channel velocity for each bed type is presented in Table 7.5.2. The recommended maximum permissible velocity depends on the condition of the channel.

TABLE 7.5.2 MAXIMUM PERMISSIBLE CHANNEL VELOCITIES FOR MOVIFIEV CONTOUR BANKS/BEVS FOR SMALL CROPS

VEGETAL MAXIMUM RETARDANCE PERMISSIBLE TYPE CONDITION OF CHANNEL CATEGORY VELOCITY m/sec

1 Some grass, bare fallow E 0.5* at times, cropped at times.

2 Poor grass cover. E 0. 8

3 Good grass cover c 1. 7 which should be slashed regularly.

4 Vigorous grass cover B 1.7 which cannot be slashed.

* 0. 5 was selected to reduce the scouring risk during the short bare fallow period. 7-21

7.5.5 Channel Gradient and Depth of Flow

Channel gradients and the depth of flow for each type are documented in Appendix VII.

7. 5.6 Constructed Bank Height

Constructed bank height is determined by adding an allowance for settlement as set out in Section 7. 4.7. An allowance for freeboard is not needed (see Section 7.4. 7).

7.5.7 Furrow Specifications

(a} Ma;x;imwn Permissible Velocities

The maximum permissible velocity for row furrows is the same as for the bare earth channels in normal contour banks (see Table 7.4.3).

(b) Ma;x;imwn Furr� Gradient

Maximum permissible furrow gradient based on furrow cross sections measured in the field are presented in Table 7.5. 3 for the A�s. The velocities achieved for gradient� from 0.1 to 10% are shown in Appendix VIII. c TABLE 7.5.3 MAXIMUM PERMISSIBLE GRADIENTS FOR ROW

FURROWS FOR THE AMUo COMMONLY USEV FOR SMALL CROPPI NG

MAXIMUM PERMISSIBLE AMUs GRADIENT (%)

Merritts, CMI (U), CDI (U), 3 CVDI (U), CDP (TC) and AMUs of the Basalt East and Basalt West LRAs.

FS-MP (G) and AMUs of the 4. 5 Basaltic Red Soils LRA with the exception of Merritts. 7-22

7.6 ·SPECIFICATIONS FOR DIVERSION BANKS

The differences.between contour banks and diversion banks are:

(i) Diversion banks have grassed channels.

',(ii) . Diversion banks generally maintain. their .. trapezodial cross section after construction.

Diversion banks are used in the Grow's Nest District to:

(i) Protect cultivation from runoff from areas higher up the slope.

(ii) To divert water into or from farm dams.

(iii) To divert water from unstable eroding areas into pasture.

Summary specifications for diversion banks are presented in Table 7. 6. 1 - summary sheets 1 and 2. Those soils not suited to contour bank construction are also unsuitable for the construction of diversion banks (see Section 7. 4.1). Diversion banks are however, constructed on the Kenmuir, BSs, BFs and Cabarlah.

Grass is present in the channel but growth is often poor due to removal of surface soil during construction. Recommendations are based on natural grass regrowth and not sowing and fertilizing of species. For design purposes the following values are used.

(i) Retardance category D with a maximum permissible velocity of 1. 0 m/sec for those suitable soils of the Marburgs, Granites, Metamorphics and Basaltic Red Soils LRAs.

(ii) Retardance category C with a maximum permissible velocity of 1. 2 m/sec for the soils of the Basalt East and Basalt West LRAs. These AMUs have a more stable and more fertile subsoil than those in (i) above.

(iii) 1 in 10 design frequency.

(iv) Where a gully line enters a diversion bank, the channel gradient can be increased by a maximum of 0. 5% for approximately 30 m.

The design specifications fordiversion banks are presented in Appendix IX. The depth of flow, channel width and channel gradient for the peak flow for two retardance values are presented in Table 7. 6. 2. The channel gradient is slightly higher than that recommended for contour banks. 7-23

TABLE 7.6.1 SUMMARY SPECIFICATIONS FOR

DIVERSION BANKS - SHEET 1

MAXIMUM SOIL PERMISSIBLE RETARDANCE LRA AMU SUITABILITY VELOCITY CATEGORY ra/sec

Basalt West Kenmuir s 1.0 c Purrawunda s 1.2 c

Basalt East BSs s 1.0 c BFs s 1.2 c BSd s 1.2 c BFd s 1.2 c BFwd s 1.2 c

Basaltic Red Cabarlah s 1.0 c Soils Pechey s 1.0 D Palmtree s 1.0 D Geham s 1.0 D Ravens bourne s 1.0 D Pinelands 1 and 2 s 1.0 D Merritts s 1.0 D

Marburgs CSI (TC) MF ns FSI (TC) MF ns CSI (U) MF ns FSI (U) MF ns CMI (TC) MF ls 1.0 D CDI (TC) MF s 1.0 D CSH (TC) MF s 1.0 D CMH (TC) MF s 1.0 D FMH (TC) MF s 1.0 D CS-MP (TC) MS s 1.0 D FS-MP (TC) MF s 1.0 D FS-MP (TC) MS s 1.0 D

Granites CSI (U) Gr ns CMI (U) Gr ls 1.0 D CS-MP (TC) Gr s 1.0 D CDP (TC) Gr s 1.0 D

Metamorphics CSI (TC) M ns CSI (U) M ns CS-MP (TC) M s 1.0 D FS-MP (G) M s 1.0 D

Alluvium Waco 5 1.2 c Al s 5 1.2 c Al w 5 1.2 c Al h s 1.2 D

s � suitable; ls less suitable; ns not suitable. 7-24

TABLE 7.6.1 SUMMARY SPECIFICATIONS FOR

DIVERSION BANKS - SHEET 2

(i) Constructed Bank Height

H= d+ f+ s equation 7. 3

d = design depth of flow - see Table 7.6.2 f = freeboard s = settlement (% of (d + f) depending on AMU)

(ii) Design Frequency

1 in 10. 7-25

TABLE 7. 6. Z VEPTH OF FLOW, CHANNEL WIVTH ANV CHANNEL GRAVIENT FOR A RANGE OF PEAK FLOWS ANV RETARVANCE

CATEGORIES FOR DIVERSION BANKS

GlANNEL DEP1H OF CHANNEL PEAK FLOW RET ARDAi'lCE WID1H FLOW GRADIENT (cumec) CATEGORY (m) (m) (%)

1.5 c 3. 0 0.5 0.4 or 0.5 D 3.0 0.5 0.4

1.5 - 2.5 c 3.0 0.6 0.4 or 0.5

D 3.0 0.6 0.4

2.5 - 3.5 c 3.0 0. 7 0.4 or 0.5 D 5.0 0.6 0.3 3.5 - 4. 5 c 3. 0 0. 8 0.4 or 0.5 D 5.0 0.7 0. 3

Constructed bank height is calculated from equation 7. 3 in section 7.4.6 for contour banks. Freeboard is increased by 10 - 20% of that used for contour banks to compensate for the effect from grass growth that may occur during the summer months.

The special construction techniques required for soils normally not suitable for diversion bank construction are set out in section 7. 4.10 for contour banks. Diversion banks on these soils should be designed with lower channel velocities. The ground under the diversion bank should be ripped before construction to ensure binding of the bank to the underlying surface.

Diversion banks require less maintenance than contour banks, as the channel is not cultivated and siltation occurs infrequently. However, maintenance is critical as failure of a diversion bank will result in contour bank failures lower down the slope.

Planting and fertilizing of the channel is generally not practiced. This would, however, provide added stability to the channel. 7-26

7.7 SPECIFICATIONS FOR PONDAGE BANKS

Pondage banks are level diversion banks with partially closed off ends. They are designed to hold as much runoff water as possible in areas where outlets are on unstable sites or unsuitable soils.

Pondage banks are used in the Craw's Nest District to:

(i) Protect cultivation where a diversion bank outlet is not available e.g. a creek flat between a steep hill and a creek with very steep banks.

(ii) Control actively eroding gullies in pasture on unstable soils.

Soils that are not suited to contour bank construction are also unsuitable for the construction of pondage banks (see section 7.4.1) .

Ideally pondage banks should hold the total runoff of the catchment for a 1 in 10 design frequency. This is often impractical due to the excessive bank height needed. As a minimum requirement, pondage banks are designed with an additional 0.5 m added to the constructed bank height specifications for a diversion bank (see section 7.6 ).

Outlets can be at one or both ends depending on where the safest outlet exists. The outlet should be at least 0.3 m below the settled bank height.

Construction and maintenance are the same as for diversion banks. 7-27

7.8 SPECIFICATIONS FOR SPREADER CHANNELS

Spreader channels are level channels, used to spread concentrated flows of runoff onto grassland.

Those soils which are not suitable for the construction of contour banks are unsuitable for the construction of spreader channels (see section 7.4.1).

Spreader channels are used for example to:

(i) Divert water away from unstable areas such as eroding waterways or creeks. In this instance, the stability further down stream of likely points of concentration of the diverted runoff should also be considered.

(ii) Spread runoff water from cultivation or natural depressions onto grassland.

Spreader channels are generally not designed. However the following construction features are recommended:

(i) Runoff water is diverted into the spreader channel by way of a contour or diversion bank. At the change over point, the channel from the contour or diversion bank is continued but the soil is pushed to the uphill side of the channel. This construction technique enables water to run out over the front edge of the spreader channel when full. Because of this construction method, the capacity of the spreader channel is less than the capacity of the contributing bank.

(ii) The gradient in the first section of the spreader channel is 0.5% gradually reducing to level over

a distance of 20 - 30 m. This will assist in filling the entire channel before the water runs out. The channel should be marked out at 3 m intervals to ensure an even outflow.

(iii) The structure should be maintained to ensure an even outflow and low spots in the channel should be repaired on a regular basis. 7-28

7.9 SPECIFICATIONS FOR WATERWAYS

7.9.1 Introduction

Only a small number of waterways have been constructed in the district. In most cases runoff water is diverted into natural depressions or onto grassland. Some waterways are required across creek flats.

It is desirable to locate constructed waterways in the natural depression. If, however, the siting of the waterway in the natural depression hinders farm operations greatly or if the natural depression is badly eroded, perched waterways are used. The location of stable waterway outlets into creeks can be a problem and in such cases waterways should not be constructed.

The erosion of waterways has always been a problem in the district. The major reason for this appears to be a lack of proper establishment and maintenance of grass cover in the waterway.

Summary specifications for waterways are presented in Table 7.9.1 - summary sheets 1 and 2.

7.9.2 Suitability of Soi Is and Sites for Waterway Construction

Waterways should not be constructed on:

(i) FSI (TC), CSI (TC), FMI (TC), CMI (TC) due to the shallow depth of the surface A horizon overlying a very dispersible and erodible clay subsoil.

(ii) Kenmuir, BSs, BFs and Cabarlah due to the shallow soil depth to parent material.

Unless it is totally unavoidable, waterways should not be constructed on the following soils:

CSI (U), FSI (U), CMI (U) , FMI (U), CS-MH (TC), FS-MH (TC) .

If the construction of waterways can not be avoided on these unsuitable soils (e.g. to carry water from better soils above), special construction techniques should be used (see section 7.9.9).

Soils such as CS-MP (TC), FS-MP (TC) and soils of the Basaltic Red Soils LRA also present problems with waterway stabilisation due to the unstable and/or infertile subsoil. Special construction techniques should be used (see section 7.9.9).

Waterways should not be located in unstable or eroding depression lines.

Farming operations have also to be considered before a waterway is located (e.g. in a graingrowing area, short runs between waterways should be avoided). 7-29

TABLE 7.9.1 SUMMARY SPECIFICATIONS FOR UIATERWAYS

SHEET

MAXIMUM GR ASS SOIL PERMISSIBLE SUITABLE CONSTRUCTION LRA AMU RETARDANCE SUITABILITY VELOCITY GRASS SPECIES TECHNIQUE CATEGORY (m/sec)

Basalt West Kenmuir ns

Purrawunda s 1.2 C/B Kr, Ks, A, I N

Basalt East BSs ns

BFs ns

BSd 1.2 C/C Kr, Ks, A, R, I N

BFd s 1.2 C/C Kr, Ks, A, R, N

BFwd 1.2 C/C Kr, Ks, A, R, N

sasaltic Red Cabarlah ns Kr, Ks, R,

Soils Pechey s 1.2 C/C or D/C Kr, Ks, R, T

Palmtree s 1.2 C/C or D/C Kr, Ks, R, N

Geham s 1.2 C/C or D/C Kr, Ks, R, T

Ravens bourne s 1.2 C/C Kr, Ks, R, N

Pinelands 1 and 2 s 1.2 C/C Kr, Ks, R, N

Merritts s 1.2 C/C Kr, Ks, R, N

Marburgs CSI (TC) MF ns

FSI (TC) MF ns

CSI (U) MF ns

FSI (U) MF ns

CMI (TC) MF ns

CD! (TC) MF s 1.0 C/C or D/C A, R, T

CSH (TC) MF ls 1.0 C/C or D/C A, R, D

CMH (TC) MF ls 1.0 C/C or D/C A, R, D

FMH (TC) MF ls 1.0 C/C or D/C Kr, Ks, R, I D

cs.:.MP (TC) MS s L2 C/C A, R, I T

FS-MP (TC) MF s 1.2 C/C or D/C Kr, Ks, R, I T T FS-MP (TC) MS s 1.2 C/C or D/C Kr, Ks, R,

Granites CSI (U) Gr ns

CMI (U) Gr ns T CS-MP (TC) Gr s LO C/C or D/C Kr, Ks, R, T COP (TC) Gr s 1.0 C/C or D/C Kr, Ks, R

Metamorphics CSI (TC) M ns

CSI (U) M ns

CS-MP (TC) M s 1.2 C/C or D/C Kr, Ks, R, T

FS-MP (G) M s 1.2 C/C or D/C Kr, Ks, R, T

1.2 N Alluvium Waco s C/B Kr, Ks, A, I 1.2 Kr, Ks, A, R, Al s s C/C or C/B I N 1.2 �s, R, N Al w s C/C or D/C Kr, A, 1.0 Al h ls C/C or D/C Kr, Ks, A, R, I D

Kr Kikuyu runners; A African star; N Normal;

Ks Kikuyu seed; Indi3n bluegrass; T Replace top soil;

R Rhodes; c Creeping bluegrass; D No disturbance to channel; 7-30

TABLE 7.9.7 SUMMARY SPECIFICATIONS FOR WATERWAYS

SHEET Z

(i) Waterway Type

Trapezoidal with flat bottom because trickle flow s do not occur in the district.

(ii) Design Frequency

(a) 1 in 10 for waterways in natural drainage lines

(b) 1 in 50 for perched waterways (c) Reduce the design frequency for very large waterways.

(iii) Constructed Bank Height

H = d + f + s

d = design depth of flow

f = freeboard s = settlement (% of (d+f ) depending on the AMU).

(iv) Stabilisation

(a) Establish suitable grass species (b) Fertilize (c) Keep runoff water out of waterway until 60% grass cover (d) Careful selection of waterway outlet into the creek.

(v) Maintenance

(a) Fertilize and slash on a regular basis (b) Permanent fencing to exclude cattle (c) Repair any structural damage immediately. 7-31

7.9.3 Waterway Channe I Shape

Trapezoidal or parabolic waterways are both stable, but in small runoff events water will tend to meander more in waterways with a flat bottom. In the Crow's Nest District, where trickle flows do not occur frequently, waterways with a flat bottom are suitable. Waterways with a flat bottom are easy to construct but require careful checking after construction to ensure a minimum side slope.

Waterway bank batters should be 3 in 1 in grain and grazing areas and in small crop areas should be 4 in 1 to facilitate crossing with farm implements.

For small catchments in small crop areas the table drain of the farm road can be designed as a waterway. These are constructed with a triangular cross section with side slopes not exceeding 1 in 1. The actual farm track may be used as a waterway if it is surfaced with non erodible material such as concrete.

In grain and grazing areas, the proportion of the depth of flow below ground level is highly variable. In small crop areas, waterways should be constructed completely below the surface so that runoff from the furrows and banks can flow readily into the waterway. Farm drainage will be improved by subsurface waterways.

7.9.4 Design Frequency

(i) Natw>al Depressions

Most natural depressions in the Crow's Nest District are very deep with capacities exceeding the 1 in 100 design frequency and generally detailed design is not required. However, in shallow depressions a bottom width should be left in grass to handle the 1 in 10 design frequency. Outlets should be grassed and stabilised before contour banks are discharged into natural depressions.

(ii) Constvueted Wate�ays

Waterways are designed for a 1 in 10 return period with the following exceptions:

(a) Perched waterways (located away from the natural depression) are designed for a 1 in 50 return period, because of the potential for damage to the contour bank system when a waterway bank breaks through.

(b) For larger catchments where the 1 in 10 bottom width exceeds 30 metres, it may be possible to:

reduce the return period or design a maximum waterway width. 7-32

For waterways designed with either a reduced return period or a maximum width, the design velocity should not exceed 1.2 m/sec and the landholder should be consulted on the increased risk of failure.

7.9.5 Vegetal Retardance Categories

Vegetal retardance categories are determined by measuring the height and density of the grass cover.. Therefore these categories vary with the growth of the sward. When the waterway design is based on a certain category, the growth of the cover has to be up to that standard to provide an effective protection against waterflow.

(i) Grain and Grazing Areas

(a) Soils with a moderate fertility Retardance C for status or a low erodibility. velocity and capacity.

(b) Soils with a high fertility Retardance C for status especially in drainage velocity and lines with a better than retardance B for average grass growth in capacity. summer.

With fertilization Retardance C for velocity and capacity.

Without fertilization Retardance D for (expected that the velocity and landholder will not retardance C maintain grass for capacity. growth)

(ii) Small Crop Areas (better grass growth due to irrigation and fertilization of the erop)

(a) Waterways crossed by Retardance C for traffic. velocity and capacity.

(b) Waterways not crossed Retardance B for by traffic. velocity and capacity.

Vegetal retardance categories can be determined in the field with the use of the Modified Ellinbank Pasture Meter (EPM) or drop board (Truong, 1979). 7-33

7.9.6 Maximum Permissible Velocity

Maximum permissible velocities vary with vegetal retardance, and soil erodibility.

( i) Grcr:in and Grazing Areas *

(a) Stable soils 1.2 m/sec (b) Unstable soils 1.0 m/sec

(ii) Small Crop Areas 2. 2 m/sec.

7. 9. 7 Design Depth of Flow

The design depth of flow and bottom width for the l in 10 design frequency are presented in Appendix X and XI for grain and grazing areas. The design depth of flow for the l in 10 design frequency, a retardance value of C and a maximum permissible velocity of 2.2 m/sec are presented in Appendix XII for table drain and trapezoidal waterways in small crop areas.

7.9.8 Constructed Bank Height

Constructed bank height is determined from the equation: H=d+f+s equation 7. 3 where H constructed bank height (m) d = design depth of flow (m) f = freeboard (m) s = allowance for settlement % of (d+ f)

Freeboard of 0.15 m is added to allow for small changes in the bed slope and standing waves that can occur at curves in the waterway. Freeboard is not added for waterways in small crop areas as the waterway runs straight down the hill.

The allowance for settlement is tabulated in Table 7.4.4. Settlement is not required for sub surface waterways.

7.9.9 Waterway Construction

Waterway construction techniques are explained in an advisory leaflet (Lehmann and Bartels, l978b).

Dozers and graders have both been used successfully for the construction of waterways. Generally a dozer is preferred for large waterways and a grader for very small waterways.

The specifications of the waterway, especially the cross section should be checked after construction. In waterways with a flat bottom the side slope should not exceed 0.2%. It is especially important to check the side slopes of the bottom of perched waterways cut into the side of the hill. � * ese yelocities for the g!ain and grazing areas are lower than those g1ven 1n the Queensland So1l Conservation Handbook. However by adding 0.15 m freeboard, velocities will be.close to those in the Handbook when the waterway runs at full capac1ty. 7-34

On those soils where the existing natural grass cover should not be disturbed during construction (see section 7.9.2), waterways should be designed with a very wide bottom and with banks no higher than 10 em - just enough to keep the water in the channel. The banks should be constructed from the outside, leaving the waterway bottom undisturbed. The subsequent channel on the outside of the waterway should be blocked off every 25 m.

For those soils where the topsoil should be replaced during construction (see section 7.9.2) , waterways should be constructed in sections in the following manner:

(i) Push the topsoil onto a lower section. (ii) Construct the waterway bank with the subsoil. and (iii) Push the topsoil back into the waterway channel.

7.9. 10 Grassing of Waterways

(i) Grass Species

Rhodes grass and kikuyu are the two main species currently used and accepted by the local farmers. Rhodes grass is more popular as it can be easily established from seed.

In addition to these two species, African star grass, and Indian bluegrass have shown promise in other districts of comparable climatic and soil conditions and could be tried out in the Crow's Nest District. Suitable grass species for the AMUs are listed in Table 7.9.2.

KikUYU

This species is currently being used in all LRAs. However, due to its high moisture and fertility requirements, it is less suitable for the coarse textured surface soils of the Granites, Metamorphics and Marburgs LRAs.

In the past, Kikuyu has been planted from runners. This method is time consuming and even under favourable weather conditions takes a long time to provide an adequate cover. Two seeded strains are now commercially available (Whittet and Breakwell), but have not been used in the district.

Whittet tends to clump if allowed to grow unchecked. It should be kept fairly short with either grazing or slashing. Germination can be a problem and initial growth is slow.

Breakwell is ground hugging but is susceptible to rust in areas with a rainfall in excess of 900 mm - i.e. in climatic zone A2 and in parts of climatic zones Al and B. Germination can be a problem.

To maintain a good cover of kikuyu, annual fertilizing is essential especially on the less fertile soils. Maintenance fertilizer should be applied early in spring to reduce winter weeds through increased competition from the grass. 7-35

TABLE 7.9.2 SUITABLE WATERWAY GRASS SPECIES FOR THE AML/6

LRA AV.U GRASS SPECIES

Basalt West Kenmuir Purrawunda Kr, Ks, A, I

Basalt East BSs ) BFs ) BSd ) Kr, Ks, A, R, I BFd ) BFwd )

Basaltic Red Soils Cabarlah ) Pechey ) Palmtree ) Geham ) Kr, Ks, R, I Ravens bourne ) Pine 1 ands 1 and 2 ) Merritts )

Marburgs CSI (TC) MF FS I (TC) MF csi (U) MF FSI (U) MF CMI (TC) MF CDI (TC) MF A, R, I CSH (TC) MF A, R, I CMH (TC) MF A, R, I FMH (TC) MF Kr, Ks, R, I CS-MP (TC) MS A, R, I FS-MP (TC) MF Kr, Ks, R, I FS-MP (TC) MS Kr, Ks, R, I

Granites CSI (U) Gr CMI (U) Gr CS-MP (TC) Gr Kr, Ks, R, I CDP (TC) Gr Kr, Ks, R, I

Metamorphics CSI (TC) M CS I (U) M CS-MP (TC) M Kr, Ks, R, I FS-MP (G) M Kr, Ks, R, I

Alluvium Waco Kr, Ks, A, I Al s Kr, Ks, A, I Al w Kr, Ks, A, R, I Al h Kr, Ks, A, R, I

Kr = Kikuyu runners; A • African star grass;

Ks = Kikuyu seed; R = Rhodes grass; I = Indian bluegrass; 7-36

Rhodes Grass

Although Rhodes grass does not provide a very good surface cover it is most popular as it can be established from seed and often establishes naturally from surrounding areas.

Rhodes grass can be planted either by itself or in combination with Indian bluegrass. It is suitable for all LRAs and climatic zones. Although its fertilizer requirement is lower than kikuyu, a maintenance programme is required to maintain an effective cover.

Pioneer and Callide are the most commonly used strains in the district. As these two cultivars are tufted, the better spreading cultivar Katambora is recommended if seed can be obtained.

African Star Grass

This grass can provide an excellent cover when properly established. It is ground hugging and very drought resistant. It can spread quickly under good moisture conditions, but has to be planted by runners as seed viability is extremely low.

African star grass can become a weed in cultivation in high rainfall areas especially on the lighter textured soils. Therefore it is not recommended for areas where annual rainfall exceeds 850 mm. On the other hand it provides a very good cover on waterways on the loamy textured soils of the Marburgs LRA where cultivation is not anticipated.

African star grass will colonize gullied areas better than kikuyu and is therefore more suitable in rehabilitation of eroded waterways.

Indian �lue Grass

This grass possesses most of the desirable characteristics of a waterway grass. It can be sown from seed and thrives on soils ranging from heavy clays to sandy loams. It is very drought tolerant. It is fairly sensitive to frost which kills most top growth but the ground layer will grow again in spring when moisture is available.

It can be successfully established in south east Queensland and an adequate cover can be obtained 12 months after sowing.

Weed control in the first two years is essential in the establishment of this species.

(ii} Grass Establishment

A deep and fine seedbed can cause serious erosion in a waterway, even when contour banks do not discharge into it. A firm and shallow seedbed is recommended to reduce soil loss. A reasonably good seedbed can be prepared with minimum soil disturbance on sandy surfaced soils and the soils of the Basaltic Red Soils LRA. Establishment is more difficult on cracking clays and hard setting loams where rolling is essential at sowing. 7-37

All grasses can be broadcast together with fertilizer and rolled in. If summer weeds are a problem, pre-emergent herbicides should be used.

Seeding rates should be at least 2 or 3 times the normal rates recommended for pasture production. Planting time varies with the area but normally the period between November and February is recommended.

In the first few years, weed control is often needed to promote the sown species. Strategic use of herbicides and/or slashing will provide effective control.

Research work in other districts indicates that a cover crop of oats or barley planted in autumn or millets in early spring may aid grass establishment in the summer. The cover crop protects the waterway surface against high intensity storms in early summer and also provides mulch for grass establishment. To reduce moisture and light competition the cover crop should be sprayed with non selective herbicides such as Round Up prior to sowing of the grass. Seed and fertilizer are broadcast into the dead mulch and rolled in with tractor tyres. Weed control is normally needed during the first two years to ensure a satisfactory grass cover by reducing weed competition.

(iii) Fertilizer Requirements

To discourage weed growth, fertilizer rates are kept to the minimum level at planting. Therefore, follow up applications are essential. The recommended rates are as follows:

ESTABLISHMENT MAINTENANCE LRA (kg/ha) kg/ha/year

Basalt West Urea - 80 Urea - 50

( Urea - 80 Basalt East Urea - 50 ( Superphosphate - 100

Basaltic Red Soils, ( N.P.K. - 100 Urea - 50 Marburgs and ( (approx. 10.10.10 Superphosphate - 50 Metamorphics ( Urea - 50

Alluvium (except Waco) N. P.K. -50 Urea - 50

7.9.11 Waterway Stab i I i ty

Most damage to waterways occurs in the first 2 years before adequate grass cover is established. This damage can be decreased by:

(i) Not letting runoff water into the waterway until at least 60% ground cover has been achieved - even if this takes 3 years. When the ground cover is about 40%, the top contour banks are allowed to empty into the waterway to provide additional moisture for grass growth. The remainder of the banks are connected to the waterway once the ground cover exceeds 60%. 7-38

(ii) Adhering strictly to waterway specifications in this chapter and checking that construction standards meet these specifications.

(iii) Considering soil stability before selecting the site (section 7.9.2).

(iv) Grassing and fertilizing the waterway as recommended in section 7.9.10.

(v) Using permanent pasture as a disposal area wherever possible or constructing the waterway banks from the outside before a pasture is broken up.

(vi) Careful selection and grassing of the waterway outlet into the creek. Most creeks in the district have steep banks and stable outlets are not always easy to find. In extreme cases, on unstable soils, grass strips should replace a contour bank/waterway system.

(vii) On highly erodible soils, surface stabilizers such as Holdgro or Enviromat should be used to provide extra protection at contour bank outlets.

(viii) Temporary fencing of waterways to keep cattle out.

(ix) Not using the waterway as a convenient access track.

7.9.12 Maintenance of Waterways

Fertilizing and slashing should be undertaken on a regular basis. Slashing is particularly important in small crop areas where regular irrigation and fertilization of crops can produce excessive grass growth which can block the flow of water.

On deep, cracking clay soils on steep slopes, invasion by Queensland bluegrass could make waterways less stable. Kikuyu, especially, requires high levels of nitrogen to compete against other grasses.

Established, stable waterways can fail if overgrazed. Permanent fencing to exclude stock is recommended especially for critical areas, such as steep eJreekbanks at the outlet of the waterway.

The waterway should not be used as a convenient access track. Adequate precautions should be taken during the planning stages to prevent this happening. In the case of small crop farms, concrete tracks should be constructed if waterways are used for access.

All structural damage should be repaired immediately. 7-39

7.10 SPECIFICATIONS FOR GRASS STRIPS

There are two types of grass strips:

(i) Narrow grass strips approximately 10 m wide. (ii) Wide grass strips which occupy approximately SO% of the potentially cultivatable area.

Grass strips are used where stable contour bank outlets are not available or on those soils suitable for cultivation but not for bank construction i.e. FMI (TC) and CMI (TC) .

Grass strips are an inexpensive alternative to contour banks for areas of temporary cultivation which are to be established to improved pasture or to tree crops where a sod cover will be maintained between the trees.

The vertical interval from the centre of one grass strip to the next is based on the equation:

VI = 0.15 (s + x) - see Equation 7.1 where VI = vertical interval between the centre of each grass strip (m) s = land slope (%) x =drainage design rating for the AMU (see Table 7.4.2)

For all crops, in erosion hazard zones 1 and 2 (see chapter 9) , 10 m wide grass strips are used, whereas in zone 3 the strips should occupy 50% of the area.

Grass strips should not be used in permanent cultivation as the only control measure on long slopes where runoff water will concentrate. Any concentration of water will require cross slope drainage.

Native grasses are adequate in the strips. However if strips are surveyed after the paddock has been broken up, improved pasture species should be planted. Recommended improved pasture species are listed for each AMU in chapter 11 and Appendix XIV. Normal cultural practices to maintain pasture growth should be observed. 7-40

7.11 SPECIFICATIONS FOR PASTURE FURROHS

Pasture furrows are small level banks, spaced at approximately 3 to 8 m intervals.

Pasture furrows will reduce runoff and assist in reducing soil erosion in pastures. The ponding of water and the subsequent increased water intake will benefit pasture growth.

Pasture furrows are not recommended to improve pasture production in the Grow's Nest District. Although pasture furrows have been used with success in areas west of Miles to promote pasture growth, the cost/benefit ratio in the Grow's Nest District with a more reliable rainfall is doubtful.

Pasture furrows have been used on a trial basis to revegetate scalded eroding areas in the Grow's Nest District.

Pasture furrows have a shallow channel and can be used on all AMUs apart from the GSI (TG) and FSI (TG).

Pasture furrows are generally not designed and the distance between the furrows is determined by economic considerations. To be effective, pasture furrows should not be more than 3 to 8 m apart, depending on the land slope and AMU.

Pasture furrows are constructed either with an uphill push or a downhill push. A pasture furrow with a channel on the downhill side will give maximum benefit to the pasture, whereas a channel on the uphill side will give maximum runoff control.

A grader or a dozer with hydraulic control of the blade angle is preferred for the construction of pasture furrows. 8- 1

8. AGRONOMIC PRACTICES FOR EROSION CONTROL

8.1 INTRODUCTION

While runoff control structures will prevent major scouring they will not significantly reduce runoff nor will they adequately reduce soil erosion. Agronomic practices that will increase water infiltration and reduce soil detachment are required to reduce soil losses to acceptable levels.

Recommended agronomic practices for the Crow's Nest District are defined.

8.2 GRAIN AND FODDER CROPS

The majority of the cultivated land in the district is on land slopes between 5 and 12%. The current agronomic practices which involve the grazing of both fodder crops and grain crop stubble predispose this area to soil erosion on these land slopes. Alternative agronomic control practices are needed to reduce soil loss to acceptable levels.

Alternative practices which are recommended include:

(i) Retain crop stubble either on the soil surface or at least through incorporation. However, under the current farming system where each farmer only grows small areas of grain to support animals, the use of machinery to retain stubble and the use of chemicals to control weeds are not considered to be viable alternatives.

(ii) Delay the first cultivation to a time as close as possible to planting. This provides a surface that has been compacted and possibly roughed up by animals and with some stubble litter protection.

(iii) Practice opportunity cropping. Cowpeas and millets are suitable crops.

(iv) Sod seed fodder crops directly into pasture. Sod seeding machinery instead of the currently used combine planters will be required. There are still some technical and economic problems associated with this technique. These include competition from winter weeds towards winter crops and a lack of soil nitrification with minimum tillage operations. This latter problem may be overcome by using legumes in fodder crops and nitrogenous fertilizers in grain crops. 8-2

In addition to oats, summer legumes such as Dolichos lab lab have been sod seeded. Winter legumes such as woolly pod vetch are an alternative that should be tested.

In early trial work on sod seeding in the Craw's Nest District, germination and production were reduced significantly with less than two workings into pasture.

(v) Use summer fodder crops such as Dolichos lab lab which is an early crop with a long growing season.

(vi) Use other land use options and reduce the area required for winter fodder crops by

(a) Planting the area to improved pasture.

(b) Planting winter grasses (fescue and phalaris) and legumes (clover and medics) into existing improved or native pasture.

(c) Planting small areas of irrigated pasture of lucerne or rye grass instead of forage crops. Water requirements for rye erass are higher than tor lucerne but lucerne is not a good winter pasture.

(d) Using crop and pasture rotations. The problems associated with crop and pasture rotations and improved pastures include:

difficulties in establishing pasture in areas of unreliable rainfall (climatic zones B and C) ;

the productivity of winter pastures is low and unreliable in climatic zones B and C. Fodder crops are therefore the best alternative;

improved pastures require high inputs of fertilizer on the poorer soils.

Improved pastures are therefore seen as likely alternatives to grazing crops in:

climatic zones Al and A2; and

on those AMUs which have at least either a moderate nutrient status or moderate plant available water capacity. 8-3

8.3 HORTICULTURAL CROPS

(i) Small C�ps

Management practices which will reduce soil loss include:

(a) Fast growing cover crops such as millets or cowpeas in situations where small crops are not grown continuously. Such crops will provide cover during the growth cycle and subsequently stubble benefits.

(b) Use seedling pots to plant well advanced seedlings into the field and so reach maximum cover protection much earlier. In addition, the use of seedling pots reduces the need for a fine and firm seedbed. Seedling pots are not suitable for all small crops e.g. carrots.

(d) Use measures to both maintain surface soil stability and to improve soil nutrient status.

(ii) Tree and Vine Crops

Sod cover should be maintained between tree and vine crops. This cover should also be maintained during the establishment period.

The high and reliable rainfall in climatic zones Al and A2 are favourable for the growth of sod cover.

8.4 PASTURES

Management practices should be undertaken to maintain adequate ground cover and prevent the concentration of surface runoff. Such practices include:

(i) Establishment of sown pastures in suitable climatic zones on suitable AMUs. Details of recommended species and fertilizers are set out in chapters 6 and 11.

(ii) Regulation of stocking rates. A ground cover of 75% with an average pasture height of 15 to 25 mm is desirable. Runoff increases rapidly when ground cover drops below 75%. Carrying capacities are presented in chapter 6. On unstable soils such as CSI (TC) and FSI (TC) pastures should be grazed after rain and then destocked.

(iii) Follow the grazing management practices outlined in chapter 6.

(iv) Select stock watering points carefully to avoid stock tracks concentrating runoff water and causing soil erosion. 9-1

9. CONSERVATION MANAGEMENT SYSTEMS

9.1 INTRODUCTION

The majority of cultivated land is on land slopes between 5 and 12 % and is used predominantly for fodder cropping of oats and grain cropping of barley. This combination of land slope and crops in association with the rainfall erosivity and seasonal distribution (Figure 2.1) predisposes the area to a serious erosion problem. The soil must therefore be protected with conservation management systems which both control and reduce runoff and reduce soil loss.

Conservation management systems involve combinations of runoff control structures (to control runoff - see Chapter 7) and agronomic practices (to reduce runoff and soil loss - see Chapter 8) . Conservation management systems have been designed to reduce soil loss to acceptable levels and so maintain the long term productivity of the land. The level of protection must be increased as the land slope steepens.

9.2 GRAIN AND FODDER CROPPING

Interim conservation management systems (based on current land use and levels of management) for erosion hazard zones 1 to 4 are presented in Table 9.1. The slope limits for each AMU for the erosion hazard zones are presented in Table 9.2. The slope limits for the various soils are governed by soil erodibility which is presented in Table 9. 3.

Areas that exceed the slope limits of zone 3 should be returned to native or improved pasture. In some cases, sod seeding of fodder crops into pasture with the use of contour banks may be an acceptable alternative. Grass strips must replace contour banks where suitable outlets are unavailable.

Eroded phases should be treated as the normal phase in the next highest land slope category. For example an eroded phase with the land slope of erosion hazard zone 1 should be treated with erosion hazard zone 2 specifications. Eroded cultivated land that is classified as zone 4a should be returned to pasture and the rehabilitation measures in Chapter 10 should be undertaken. 9-2

TABLE 9.1 INTERIM CONSERVATION MANAGEMENT SYSTEMS FOR THE EROSION HAZARD

ZONES FOR VRYLANV GRAIN ANV FOVVER CROPPING

LAND USE ZONE 0 ZONE 1 ZONE 2 ZONE 3 ZONE 4a AND 4b** (i) (ii)

+ Grain cropping N DSCB/SI or DSCB/SM or SSCB/SM NR NR SSCB SSCB/SI

Fodder cropping N SSCB or SSCB/MT or SSCB/SS or SSCB/SS NR 10% pasture/ 30% pasture/ GR (50%)* or DSCB SSCB 50% pasture/ SSCB

Fodder cropping/ N SSCB SSCB/SI SSCB/SM NR NR Grain cropping (grain) and (grain) and MT (fodder) MT (fodder) (fodder cropping should not exceed 3 in 10 years)

N = no special conservation management required;

NR = not recommended. DSCB double standard spaced contour banks; SSCB standard spaced contour banks; SI stubble incorporation; SM stubble mulch; MT minimum tillage; SS sod seeding;

GR (SO%) = grass strips SO% of area.

* Treatment if soils are not suitable for the construction of contour banks.

** Erosion hazard zones 4a/4b have been divided into:

(i) areas where no timber restrictions apply (ii) areas where timber restrictions apply.

+ Grain crops include barley, wheat, early sorghum, millets and panic�. Crops such as soybeans and sunflowers require the same management levels as fodder crops. 9-3

TABLE 9.2 SLOPE LIMITS FOR THE EROSION HAZARD

ZONES FOR THE AMUI

LAND SLOPE LIMITS (%) LRA AMU ZONE 1 ZONE 2 ZONE 3

Basalt West Kenmuir NS NS NS Purrawunda 3 5 8

Basalt East BSs NS NS NS BFs NS NS NS BSd 3 5 8 BFd 3 5 8 BFwd 3 5 8

Basaltic Red Cabarlah NS NS NS Soils Pechey 3 5 8 Geham 3 5 8 Merritts 3 5 8 Ravens bourne 4 6 10 Pinelands 1 and 2 4 6 10 Palm tree 4 6 10

Marburgs, CSI (TC) NS NS NS Metamorphics CSI (U) NS NS NS and FSI (TC) NS NS NS Granites FSI (U) NS NS NS CMI (TC) 2 FMI (TC) 2 CMI (U) 3 FMI (U) 3 CSH (TC) 3 5 8 CMH (TC) 3 5 8 FMH (TC) 3 5 8 CS-MP (TC) 3 5 8 FS-MP (TC) 3 5 8 FS-I'P (G) 4 6 10 CDl (TC) 4 6 10 C:JP (TC) 4 6 10

NS ; Not suitable for permanent cultivation. 9-4

TABLE 9. 3 EROVIBILITV FACTORS (K FACTOR) FOR THE AMU6

SOIL ERODIBILITY (K factor after LRA AMU Wischmeier and Smith, 197 8)

Basalt West Kenmuir 0.26 Purrawunda 0.3 8

Basalt East BSs 0.26 BPs 0.26 BSd 0.36 BPd 0.38 BFwd 0.38

Basaltic Red Soils Cabarlah 0.26 Pechey 0.26 Palmtree 0.24 Geham 0.26 Ravens bourne 0.24 Pinel ands 1 and 2 0. 24 Merritts 0.36

Marburgs CSI (TC) MF 0.42 PSI (TC) MF 0.45 CSI (U) MF 0. 25 PSI (U) MF 0. 31 CMI (TC) MP 0.37 CDI (TC) MF 0. 31 CSH (TC) MP 0.37 CMH (TC) MP 0.37 FMH (TC) MP 0.37 CS-MP (TC) MS 0.28 PS-MP (TC) MF 0.28 PS-MP (TC) MS 0. 28

Granites CSI (U) Gr 0.25 CM I (U) Gr 0.21 CS-MP (TC) Gr 0.24 CDP (TC) Gr 0.18

Metamorphics CSI (TC) M 0.42 CSI (U) M 0.25 CS-MP (TC) M 0.28 FS-MP (G) M 0. 25 9-5

9.3 HORTICULTURAL CROPS (Tentative specifications only)

9. 3 .. 1 Small Crops

Erosion on small crops can be controlled by a combination of:

(i) A system of runoff control structures. These can be modified contour banks/beds or normal contour banks or parallel contour banks at double* standard bank spacings.

(ii) Agronomic practices in Section 8.2.3.

The land slope limits for soils for the erosion hazard zones for grain cropping should be observed.

9.3.2 Tree and Vine Crops

The normal practice is to keep a sod cover between the rows. When a good sod cover is maintained, soil conservation measures or contour planting is not required. When temporary cultivation is necessary prior to planting, it is recommended to use grass strips. Grass strips will not interfere with the tree or trellis layout.

The tree clearing land slope limits (Table 9.4) for the AMUs should not be exceeded for the establishment of tree and vine crops.

9.4 PASTURES

Management of pasture to prevent soil erosion involves:

(i) The use of sound agronomic practices, and (ii) The observance of tree clearing limits.

Runoff control structures are not an economic proposition and if sound agronomic management is practised are not required. Pasture furrows and contour ripping as indicated in Chapter 7 will be advantageous in some situations. Contour banks or grass strips should be used if land is cultivated for a considerable period for the establishment of improved pastures.

( i J Agronomic

The agronomic management practices for production (Chapter 6) and for erosion control (Chapter 8) should be observed. In particular overgrazing should be avoided.

* Double standard spacings will result in higher channel velocities than with single spacing. This does not matter as the channels are grassed. 9-6

(ii) Tree Clearing Limits

Recommended tree clearing restrictions are set out in Table 9.4 for those soils with impermeable sub soils of the Marburgs, Granites and Metamorphics LRAs. For all other AMUs, the cost of development, the control of woody weed regrowth and the control of soil erosion become limiting factors to development on land slopes in excess of 17 to 20%. In addition, trees on higher land slopes offer watershed protection and long term protection against the possibility of soil salinity in low lying areas.

TABLE 9.4 RECOMMENDED UPPER LAND SLOPE LIMITS FOR TREE CLEARING FOR THE HIGHLY ERODIBLE SOILS OF THE MARBURGS LRA IN THE CROW'S NEST DISTRICT

AMU UPPER LAND SLOPE LIMIT (%)

CSI (TC) 4 CSI (U) 7 FSI (TC) 4 FSI (U) t CMI (T C) 4 CMI (U) 7 FMI (TC) 4 CMI (U) 7 10-1

10. SPECIFICATIONS FOR SPECIAL PURPOSE LAND USE

10.1 SPECIFICATIONS FOR SUBDIVISION AND FARM AMALGAMATION

10.1.1 Introduction

Subdivision and farm amalgamation are undertaken in the district.

Subdivision falls basically into three categories:

(i) Subdivision of a large property into smaller farms.

(ii) Subdivision of land into semi-rural land for hobby farms.

(iii) Subdivision of land into residential blocks with a maximum size of one hectare.

There is a great interest in subdivision for semi-rural and residential land, mainly in the Toowoomba - Geham - Meringandan area. This area is close to Toowoomba, has a mild climate with a reliable rainfall, an aesthetically pleasing landscape and town water available to many localities.

Both subdivision of large properties into smaller, mostly non viable farms and farm amalgamation occur on a limited scale. Amalgamation, especially in the Djuan - Douglas area, of small dairy farms is desirable, but is hampered by high land prices.

10.1.2 General Procedures for Subdivision

In the Crew's Nest Shire, plans for all subdivisions are referred by the Local Authority to the Soil Conservation Branch for comment.

In all subdivisions, whether rural, semi-rural or residential, runoff disposal has to be integrated with runoff disposal from the surrounding farming land. The Local Authority liaises with Soil Conservation Branch to determine entry and exit points of runoff disposal schemes of the surrounding rural land.

Runoff disposal in semi-rural and rural subdivisions are generally designed by the Soil Conservation Branch. Boundaries of properties within subdivisioil3for rural and semi-rural land should be located to suit a soil conservation drainage layout. The design for the stormwater disposal within residential subdivisions is generally performed by the Local Authority. 10-2

10.1.3 Recommendations for Semi-Rural Subdivision (Hobby Farms)

Semi-rural subdivisions can result in a more intensive land use and increased runoff (more buildings, yards, grain and fodder cropping, orchards, small crops, intensive grazing) . The upper limits for the AMUs (based on the upper slope limits for clearing) for semi rural subdivisions are indicated in Table 10.1

TABLE 10 • 1 SUITABILITY OF THE AMUI FOR SEMI-RURAL SUBDIVISION

LAND SLOPE (%)

AMU NOT LIHITED SUITABLE SUITABLE SUITABILITY

CSI (TC and U) , FSI (TC and U) All slopes CMI (TC) , FMI (TC) > 4 < 4 CMI (U) , FMI (U) > 7 < 7

FDI (U) , CS-MH (TC) >17 8 - 17 < 8 FS-MH (TC) , CS-MP (TC) >17 8 - 17 < 8 FSP (TC) , FMP (TC) >17 8 - 17 < 8 FOP (U) >17 8 - 17 < 8 CDI (TC) , CDI (U) >17 10 - 17 < 8 CS-MP (G) , FS-MP (G) >17 10 - 17 < 8 All other AMUs >17 <17

The shallow effective soil depth, low productivity and high soil erodibility limits the suitability of CSI (TC and U) , FSI (TC and U), CMI (TC) , FMI (TC) , CMI (U) and FMI (U) for subdivision.

Land with > 17% land slope is generally not suitable for intensive land use, road construction, dam construction, etc.

Land with limited suitability can be subdivided provided it is not used for permanent cultivation for small crops and for grain and fodder cropping. 10-3

10.1 .4 Subdivision for Residential Land

CSI (TC) and FSI (TC) should not be used for subdivision and CSI (U) and FSI (U) should be avoided. These AMUs have an effective soil depth of less than 15 em - the first two AMUs with dispersible subsoils and the latter two over rock. Septic tanks are a problem. on these soils, and have to be emptied once a week. They are poor garden soils because of their shallow depth and in low lying areas drainage problems occur. CSI (TC) and FSI (TC) have extemely erodible B horizons and would require kerbs, channels and underground drains. Stormwater outlets will erode severely on sloping land, while on low land slopes drainage is a serious problem. CMI (TC) and FMI (TC) also have dispersible subsoils (similar to those of CSI (TC) and FSI (TC) ) but because of the deeper A horizon (up to 30 em) can be used for subdivision. However they should be avoided if possible.

10.2 SPECIFICATIONS FOR REHABILITATION OF TOPSOIL QUARRIES

Disused topsoil quarries in the district have not been rehabilitated. These abandoned quarries may result in loss of productivity, increased runoff, increased erosion and release of soluble salts into the runoff water. Many of these quarries have stabilized with woody weed regrowth without rehabilitation.

Land abandoned after quarrying should be restored in such a way that the area does not present an erosion risk. Rehabilitation work would normally consist of fencing and destocking. Fertilising to promote grass growth is recommended. It may be necessary to sow pastures or to install some runoff control structures, where increased runoff presents an erosion risk to lower lying areas.

Soils with dispersible subsoils should not be quarried unless a complete reshaping and restoring of surface A horizon is carried out. Because of the high cost of these operations, the sandy shallow surfaced texture contrast soils are not suitable for topsoil quarrying.

The co-operation of the Shire Council is essential to achieve rehabilitation of quarries.

10.3 SPECIFICATIONS FOR RECLAMATION OF SEVERELY ERODED LAND

10.3.1 Introduction

The conservation management systems as indicated in Chapter 9 will prevent serious soil erosion on non eroded land. If the area is already eroded, the following measures should be undertaken to stabilize the area. These measures will in general not return the area to its original condition. 10-4

10.3. 2 Severely Eroded Cultivated Land

The following procedures are recommended:

(i) Gullies should be filled if economically possible. If this is not feasible the area should be removed permanently from cultivation and treated as eroded pasture land (see Section 10.3.3) .

(ii) Runoff control structures should be installed (contour banks, waterways) as set out in the specifications in Chapter 7. Contour banks should not be constructed until grass is successfully established in the waterway.

(iii) The paddock should be removed from commercial crop production for at least four years and planted to grass or lucerne. If the land slope exceeds the acceptable limits for eroded cultivation, the paddock should be permanently removed from cultivation.

(iv) When the area is returned to crop production, the management levels for eroded phases in Chapter 9 should be observed.

10.3.3 Severely Eroded Pasture Land

The following procedures are recommended:

(i) Reduce the stocking rate to at least one quarter of the recommended stocking rate (see Chapter 6).

(ii) Plant suitable pasture species (Chapter 6 and 11) and fertilize at double the recommended rate. for pastures. Fertilizer application will be uneconomic but will increase ground cover.

(iii) The land slope limits for tree clearing in Table 9.4 should be observed. Tree planting should be considered for very steep land slopes that have been cleared.

(iv) Woody regrowth should be controlled either by slashing or with chemical treatment rather than by bulldozing or burning.

(v) Runoff water should be dispersed and not concentrated. Pondage banks, pasture furrows or pasture ripping should be undertaken to retain water. Pasture furrows and pasture ripping are not effective if the area has severe gully erosion. 10-5

(vi) Treat eroded gullies and creek lines as indicated in Section 10.3.4.

(vii) Scalded areas should be contour ripped to increase infiltration and/or cultivated to establish pastures.

(viii) After reclamation observe the management recommendations made in this manual.

10.3.4 Eroded Gul I ies, Creeks and Waterways

The cause should be identified and rectified e.g.

(i) Cattle tracks to a watering point in a creek.

(ii) Unstable outlet area for a runoff control structure.

If this does not control the problem the following measures are recommended:

(i) The damaged area should be fenced and destocked.

(ii) Suitable grass species (African star, creeping blue grass) should be planted and fertilized at double the recommended rate for pastures. The grass should be watered if possible.

(iii) Reshaping is generally not recommended as there is a high risk that loose soil material will be washed away before grass can be established. However small pot holes and depressions should be filled with a soil/grass mixture.

In addition t'lte followine measures may be required: (iv) Concentrated flows of runoff water should be temporarily diverted to more stable areas. It should be ensured that this diverted water does not cause damage elsewhere. Contour banks should be used to divert the water if stable outlets are available and pondage banks where stable outlets are not available. Pasture furrows may be adequate if the gullies are small.

(v) Construct gully runoff control structures where appropriate.

(a) Non dispersible subsoils and gullies < 2 m deep.

Gabian Weirs - used to stabilize very large waterways; expensive and is mainly used on works of general benefit.

Loose Stone Weirs - successful on small catchments; construction is labour intensive.

Rock filling - requires large amounts of stone. 10-6

(b) Dispersible subsoils and very deep gullies

(> 2 m) •

Masonry or Sand Bag or Rock Flumes* - used to dissipate excess energy produced by a rapid change in stream base level which occurs at gully overfalls; suitable for immediate use; conve� a large discharge through a small width; high labour and/or high material costs (J. Marshall, pers. comm.).

* The success of the structure is dependent on ensuring that the energy developed by water falling over the gully head is fully dissipated in the stilling basin at the toe of the chute. In addition, the stream gradient downstream of the structure must be considered when determining the level of the stilling basin. Sidewalls must be fully protected to prevent water from high flows splashing down behind the structure. Toewalls must be inserted to prevent flows undermining the structure. 11-1

11. SUt1MARY OF MANAGEMENT PRACTICES

FOR THE AMUs

LIST OF ABBREVIATIONS

NE not economic

ND not determined

NA not applicable

s suitable

NS not suitable

LS limited suitability 11-2

11.1 MARBURGS, METAMORPHICS AND GRANITES LAND RESOURCE AREAS 11-3

MARBURGS AND METAMORPHIC$ LAND RESOURCE AREAS

FSI ITCl MF> CSI (TCl !!F AND CSI (TCJ I' M!Us

SOIL NUTRIENT STATUS Low - deficient in minor and major nutrients.

SURFACE pH 6.0 - 6.5

PLANT AVAILABLE WATER CAPACITY Very low. 4 em of plant available water stored in the surface A horizon and insignificant

quailtities in the B horizon.

PHYSICAL CHARACTERISTICS (i) Soil surface sets hard after rain when not protected by vegetation.

{ii) Sob soi1 h<> high bulk density (1.8 - 2.00 g/cc) - root penetration is difficult.

(iii) Sob soil is highly dispersible and hence erodible when exposed.

(iv) Sob soi1 has high levels of salinity and sodicity.

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE PASTURE IMPROVED SOWN PASTURE

USE SUITABILITY NS NS NS NS Limited summer NS grazing

FERTILIZER REQUIREMENTS NA NA NA NA NE NA

SUITABLE IMPROVED PASTURE SPECIES NR

PASTURE CARRYING CAPACITY (i) Native 5 - 7

(ha/b�st) (ii) Improved NA

RUNOFF CONTROL STRUCTURES (i) Contour banks NS

(ii) Waterways NS

(o) Grass species NA

(b) Fertilizer NA

(iii) Diversion and pondage banks NS

MAXIMUM PERMISSIBLE VELOCITY (i) Bare earth channel NA

(ii) Grassed waterway channel

(iii) Diversion bank channel NA

RUNOFF COEFFICIENT SOIL CATEGORY C

DRAINAGE DESIGN RATING 6.2

SOIL ERODIBILITY (K factor) 0.42 - 0.45

UPPER LAND SLOPE UNIT FOR PERMANENT CULTIVATION NA

UPPER LAND SLOPE LIMIT FOR TREE CLEARING 4%

LAND CAPABILITY CLASSIFICATION VI - VII e6, d6, m4, n4, k4 , p4, s2- 4

OTHER INFORMATION Slopes greater than 4% should be used for watershed protection.

Any fonn of management should ensure that water is spread and not concentrated.

Concentration of water will lead to rapid and severe gully erosion of the dispersible sub soil. 11-4

MARBURGS, GRANITES AND METAMORPHIC$ LAND RESOURCE

AREAS

FSI (Ul MF, CSI

SOIL NUTRIENT STATUS Low - deficient in �ajar and minor nutrients

SURFACE pH - 6. 5

PLANT AVAILABLE WATER CAPACITY Very low - 4 em of plant available water are stored to the depth of "parent material. . PHYSICAL CHARACTERISTICS - (il The soil surface sets hard after rain when not protected by vegetation.

(ii) The sub soil is dispersible.

CRAIN CROPPING FODDER r.ROPPING SMALL CROPS TREE/VINE CROPS NATIVE PASTURE IMPROVED SOWN PASTURE

USE SU ITABll ITY NS NS NS NS Limited summer NS grazing

FERTILIZER REQUIREMENTS

SUITABLE IMPROVED PASTURE SPECIES - N.R. Creeping blue grass and Siratt'o to be tried in climatic zones B and C.

PASTURE CARRYING CAPACITY (il Native - 5 - 9

(ha/beast) (ii) Improved - NA

RUNOFF CONTROL STRUCTURES - (i l Contour banks - NS

(ii) Waterways - NS

(ol Grass species - NA

(b I Fertilizer - NA

(iii) Diversion and pondage banks NS

MAXIMUM PERMISSIBLE VELOCITY - (il Bare earth channel - NA

(ii) Grassed waterway channel - NA

(iii) Diversion bank channel NA

RUNOFF COEFFICIENT SOIL CATEGORY - C

DRAINAGE DESIGN RATING - 6.8

SOIL ERODIBILITY (K factor) 0.25 - 0.31

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION - NA

UPPER LAND SLOPE LIMIT FOR TREE CLEARING 7%

LAND CAPABILITY CLASSIFICATION - (i) CSI ( U I M VII -VIII e6, d6, m4, n4, t7-8, r5

(ii) CSI ( U) Gr VI - VII e6, d6, m4, n4, r4-5, t6-7

(iii) Other units - vr"'- VII e6, d6, m4, n4

OTHER INFORMATION - Slopes greater than 4% should be used for watershed protection.

Any form of management should ensure that water is spread and not concentrated. 11-5

MARBURGS LANO RESOURCE AREA

C�\l ( TCJ �IF �MU

SOIL NUTRIENT STATUS Low - deficient in major and minor nutrients.

SURFACE pH 6.5

PLANT AVAILABLE WATER CAPACITY Low. Approximately 6 em of plant avai1able water are stored in the surface A horizon

and insignificant quanities in the B horizon.

PHYSICAL CHARACTERISTICS (i) Sub soil has a high bulk density {1.8 - 2.0 g/cc) - root penetration is difficult.

(ii}' Sub soil is highly dispersible and hence erodible when exposed.

(iii) Sub soil has high levels of salinity and sodicity.

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS Nh.TIVE PASTURE IMPROVED SOWN PASTURE

Temporary prior USE SUITABILITY NS to establishment NS NS s LS of sown pastures.

FERTILIZER REQUIREMENTS NP

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, paspalum and medics (where pH> 6.5) in all climatic zones. Creeping blue grass

and Siratro in zones B and C.

PASTURE CARRYING CAPACITY (i) Native 4.2

( ha/beast) (i i) Improved 2.6

RUNOFF CONTROL STRUCTURES (i) Contour banks LS

(ii) Waterways NS

(o) Grass species NA

(b) Fertilizer NA

(iii) Diversion and pondage banks LS

MAXIMUN PERMISSIBLE VELOCITY - (i) Bare earth channel - 0.5 m/sec

(ii) Grassed waterway channel - NA

(iii) Diversion bank channel 0.8 mjsec

RUNOFF COEFFICIENT SOIL CATEGORY - C

DRAINAGE DESIGN RATING 6.8

SOIL ERODIBILITY (K factor) 0.37

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION NA

UPPER LAND SLOPE LIMIT FOR TREE CLEARING 4%

LAND CAPABILITY CLASSIFICATION IV - VI e4-6, d4, m4, n4, s2- 4

OHlER INfORMATION (i) Contour bank outlets should be selected carefully to avoid channel cutback.

(ii) The highly dispersible clay sub soil should not be exposed to running water.

Rapid and severe gully erosion will result.

{iii) Slopes great�r than 7% should be used for watershed protection. 11-6

MARBURGS LAND RESOURCE AREA

CD!

SOIL NUTRIENT STATUS Low - deficient in major and minor nutrients.

SURFACE pH 6.0

PLANT AVAILABLE WATER CAPACITY Low. The amount stored depends on the depth of the A horizon. Insignificant amounts are

stored in the B horizon.

PHYSICAL CHARACTERISTICS (i) Sub soil h

(ii) Sub soil is highly dispersible and hence erodible when exposed

(iii) Sub soil has high levels of salinity and sodicity

GRAIN CROPPING FODDER CROPPING SMAL� CROPS TREE/VINE CROPS NATIVE PASTURE IMPROVED SOI-1N PASTURE

Temporary prior NS - except for USE SUITABILITY NS to establishment s profi 1 e �'lith A s of sown pastures. horizon > 60 em

FERTILIZER REQUIREMENTS NP NP NP NP

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, paspalum and medics (where pH> 6.0) in all c1imatic zones. White clover in A1 and A2. Kazungula Setaria in B. Creeping blue grass and Siratro in B and C.

PASTURE CARRYING CAPACITY (i) Native 2.0

{ha/beast) { ii) Improved 3.6

RUNOFF CONTROL STRUCTURES (i) Contour banks NBCB

( i i) Waterways

(<) Grass species African star grass, Rhodes grass, Indian blue grass

(b) Fertilizer N, P,K

(o) Construction technique Banks should be pushed from the outside or topsoil replaced in the channel after

construction (see construction techniques).

(iii) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY (i) Bare earth channel 0 5 mjsec

(ii) Grassed waterway channel 1.0 m/sec

(iii) Diversion bank channel 0.8 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY

DRAINAGE DESIGN RATING 6.8

SOIL ERODIBILITY (K factor) 0.31

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION - 10%

UPPER LAND SLOPE LIMIT FOR TREE CLEARING NO

LAND CAPABILITY CLASSIFICATION III IV e3-4, m3, n3 11-7

MARBURGS LAND RESOURCE AREA

CSH (TCJ f1F AND CMH

SOIL NUTRIENT STATUS Low.

SURFACE pH 6.5 -7.0

PLANT AVAILAB LE WATER CAPACITY Low to moderate. 9 em of plant available water are stored in the profile to a depth of 60 em.

PHYSICAL CHARACTERISTICS (i) Sub soil is slowly permeable and erodible if exposed

( ii) The soil surface sets hard after rain when not protected by vegetation

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE Pll_STURE IMPROVED SOWN PASTURE:

USE SUITABILITY NS s NS NS s s

FERTILIZER REQUIREMENTS NP �

SUITAB LE IMPROVED PASTURE SPECIES Rhodes grass, paspalum and medics (where pH > 6.5) in all climatic zones. Phalaris, fescue

and white clover in Aland A2. White clover in Al, A2 and B. Lucerne in A2, B and C.

Siratro in B and C.

PASTURE CARRYING CAPACITY (i) Native 3.6

(ha;beast) (ii) Improved 2.0

RUNOFF CONTROL STRUCTURES (i) Contour banks NBCB

(ii) Waterways s

(o) Grass species African star grass, Rhodes grass, Indian blue grass

(b) Fertilizer N,P ,K

(see construction techniques)

(iii) Diversion and pondage banks s

MAXIMUM PERMISSIB LE VELOCITY (i) Bare earth channel 0 5 m/sec (ii) Grassed waterway channel 1.0 m/sec

(iii) Diversion bank channel 0.8 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY

DRAINAGE DESIGN RATING 6.8

SOIL ERODIBILITY (K factor) 0.37

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION 8%

UPPER LAND SLOPE LIMIT FOR TREE CLEARING NO

LAND Ci\Pi\BlllTY Cli\SSlFlCi\TION IV e3-4, m2. n3, s2 118

MARBURGS LAND RESOURCE AREA

F�1H

SOIL NUTRIENT STATUS Low to moderate.

SURFACE pH 6.0 - 6.5

PLANT AVAILABLE WATER CAPACITY Low to moderate. 8 em of plant available water are stored in the profile to a depth of 60 em.

PHYSICAL CHARACTERISTICS (i) Soil surface sets hard after rain when not p�otected by vegetation (ii) The sub soil is dispersible

GF!AIN CROPPING FODDER CROPPING SMA_LL CROPS TREE/VINE CROPS NATJVE PASTURE IMPROVED SOWN PASTURE

USE SUITABILITY NS NS s

FE RTILIZER REQUIRE�1ENTS N and NP

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, paspalum and medics (where pH > 6.5} in all climatic zones. Phalaris and fescue

in Al and AZ. White clover in Al, A2 and B. Lucerne in A2, B and C. Siratro i� B and C.

PASTURE CARRYING CAPACITY (i) Native 0

(ha/beast) (ii) Improved 1.7

RUNOFF CONTROL STRUCTURES (i) Contour banks NBCB

(ii) Waten.�ays s

(,) Grass species Kikuyu, Rhodes grass, Indian blue grass

I b) Fertilizer NP

(iii) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY (i) Bare earth channel 0.5 mjsec

(ii) Grassed waterway channel 1.0 mjsec (iii) Diversion bank channel 0.8 mjsec

RUNOFF COEFFICIENT SOIL CATEGORY

DRAINAGE DESIGN RATING 6.2

SOIL ERODIBILITY (K factor) 0.37

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION 8%

UPPER LAND SLOPE LIMIT FOR TREE CLEARING ND

LAND CAPABILITY CLASSIFICATION IV e3-4, m2, n2, s2, p3

OTHER INFORMATION Contour bank outlets should be selected carefully to avoid channel cutback. The clay B horizon should not be exposed to running water. 11 9

MARBURGS AND METAMORPHIC$ LAND RESOURCE AREAS

FS-11P ITCl MF, FS-MP

SOIL NUYRIENT STATUS Low to moderate.

SURFACE pH - 6.0 - 7.0

PLANT AVAILABLE WATER CAPACITY Moderate - 10 em of plant available water are stored in the profiie to a depth of 90 em.

PHYSICAL CHARACTERISTICS - (i) Soil surface sets hard after rain when not protected by vegetation.

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE PASTURE IMPROVED SOWN PASTURE

USE SUITABILITY s LS s

NP after NP after FERTILIZER REQUIREMENTS continuous continuous NP cultivation cultivation

SUITABLE IMPROVED PASTURE SPECIES - Rhodes grass, paspalum and medics (if pH> 6.5) in all climatic zones. Fescue, phalaris and

kikuyu (N required on scrub soi1s) in Al and A2. Lucerne in A2. B and C. Creeping blue

grass and Siratro in B and C. Ka zungula Setaria in B. Green panic in all climatic zones

on the scrub soils.

PASTURE CARRYING CAPACITY (i) Native - 2.4

(ha/beast) (ii) Improved - 1.4

RUNOFF CONTROL STRUCTURES - (i) Contour banks NBCB

(i i) Waterways -

(o) Grass spec_ies Kikuyu, Rhodes grass, Indian blue grass. Substitute African star grass for kikuyu in CS-MP (TC) MS.

(b) Fertilizer - NP (c) Construction technique - Topsoil should be replaced in the channel.

(iii) Diversion and pondage banks -

MAXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel - 0.5 m/sec

(ii) Grassed waterway channel - 1.2 mjsec

(iii) Diversion bank channel 0.8 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY - B

DRAINAGE DE SIGN RATING - 7.4

SOIL ERODIBILITY (K factor) - 0.28

UPPER LII.N.D SLOPE LIMn FOR PER�\1\.NENT CULTIVATION - 8%

UPPER LAND SLOPE LIMIT FOR TREE CLEARING NO

LAND CAPABILITY CLASSIFICATION - (i) CS-MP (TC) M IV - VI e4-6, m2, n2

(ii) Other units III - IV e3-6, m2 11-10

GRANITES LAND RESOURCE AREA

CMI CUl GR Af'1U

SOIL NUTRIENT STATUS Low deficient in major and minor nutrients.

SURFACE pH 5. 5 6.0

PLANT AVAILABLE WATER CAPACITY LOw. 6 em of plant available water are stored to the depth of the parent material.

PHYSICAL CHARACTERISTICS - (i) Loose friable surface.

GRAIN CROPPnTG FODDER CFIOPPING SMALL CROPS THEE/VINE CROPS NATIF/E PASTURE IMPROVED SOWN PASTURE

temporary prior USE SUITABILITY NS to establishment NS NS s LS of sown pastures

FERTILIZER REQUIREMENTS NP

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, paspalum and medics (where pH> 6.5) in a11 climatic zones. White c1over in

zones Al and A2. Creeping blue grass and Siratro in zone B.

PASTURE CARRYING CAPACITY (i) Native 4.2

(ha/beast) ( i i) Improved 2.6

RUNOFF CONTROL STRUCTURES (i) Contour banks LS

(ii) Waterways NS

(a) Grass species NA

I bl Fertiljzer NA

{iii) Diversion and pondage banks LS

MAXIMUM PERMISSIBLE VELOCITY (i) Bare earth channel 0.5 mjsec

(ii) Grassed waterway channel NA

{iii) Diversion bank channel 0.8 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY B

DRAINAGE DESIGN RATING 7.4

SOIL ERODIBILITY (K factor) 0.21

UPPER LAND SLOPE Lit�IT FOR PERMANENT CULTIVATION NA

UPPER LAND SLOPE LIMIT FOR TREE CLEARING 7%

LAND CAPABILITY CLASSIFICATION IV -VI e4-6, m4, n3, t6, d4. 11-11

GRANITES LAND RESOURCE AREA

CS-MP (TCJ Ge AMU

SOIL NUTRIENT STATUS Low to moderate - deficient in N and P and possibly K.

SURFACE pH 6.5 -7.0

PLANT AVAILABLE WATE.=< CAPACITY Moderate. 10 em of plant available water are stored in the profile to a depth of 90 em.

PHYSICAL CHARACTERISTICS (i) The soil socf,ce sets hacd 'ftec caio wheo·oot pcotected by 'eget,tioo,

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE PASTURE IMPROVED SOWN PASTUHE

USE SUITABILITY s s s S - LS s s

FERTILIZER REQUIREMENTS NP NP NP NP

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, paspalum, medics (if pH > 6 5) and white clover in climatic zones Al, A2 and B.

Fescue and phal_aris in Al and A2. Lucerne in AZ and B. Creeping blue grass, Kazungula

Setaria and Siratro in B.

PASTURE CARRYING CAPACITY (i) Native 2.4

(ha/beast) (ii) Improved 1.6

RUNOFF CONTROL STRUCTURES (i) Contour banks NBCB

(ii) Waterways s

(a) Grass species Kikuyu, Rhodes grass, Indian blue grass

(b) Fertilizer N,P,K

(iii) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY (i) Bare earth channel 0.5 m/sec

(ii) Grassed wt�terway channel 1.0 mjsec

(iii) Diversion bank channel ··o.s m/sec

RUNOFF COEFFICIENT SOIL CATEGORY B

DRAINAGE DESIGN RATING 7.4

SOIL ERODIBILITY (K factor) 0.24

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION 8%

UPPER LAND SLOPE LIMIT FOR TREE CLEARING NO

LAND CAPABILITY CLASSIFICATION III - IV e3-4, m3, n2 11-12

GRANITES LA.T'ID RESOURCE AREA

COP

SOIL NUTRIENT STATUS Low to moderate - deficient in �J and P and possibly K

SURFACE pH - 6.5 - 7.0

Pl�.NT AVA1LABLE WATER Ci'IP!l.CITY \-loderate - 8 to 10 em of p1 ant available water are stored in the profile to a depth of 90 em.

PHYSICAL CHARACTERISTICS - (i) The soil surface sets hard after rain when not protected by vegetation.

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREF:/VINE CROPS NATIVE PASTURE IMPROVED SOWN PASTURE

USE SUITABILITY LS s s s

FERTILIZER REQUIREMENTS NP NP NP NP NP

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, paspalum, medics (where pH> 6.5) and white clover for climatic zones Al, A2

and B. Phalaris and fescue in Al and A2. Lucerne in A2 and B. Creeping blue grass,

Kazungula Setaria and Siratro in B.

PATURE CARRYING CAPACITY (i) Native - 2.4

(hajbeast) (; i) Improved � 1 6

RUNOFF CONTROL STRUCTURES - (i) Contour banks - NBCB

(ii) Waterways - S

(a) Grass sp�cies - Kikuyu, Rhodes grass, Indian blue grass

(b) Ferti1 izer - N,P,K

(iii) Diversion and pondage banks - S

t'l.AXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel - 0.5 m/sec

(ii) Grassed waterway channel - 1.0 m;sec

(iii) Diversion bank channel 0.8 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY - A

DRAINAGE DESIGN RATING - 8.6

SOIL ERODIBILITY {K factor) 0.18

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION - 10%

UPPER LAND SLOPE LIMIT FOR TREE CLEARING - NO

LAND CAPABILITY CLASSIFICATION - III - IV e3-4, m3, n2 METAMORPHICS LAND RESOURCE AREA

FS-MP IGl M AMU

SOIL NUTRIENT STATUS Moderate to high.

SURFACE pH 6.0- 7.0

PLANT AVAILABLE WATER CAPACITY Moderate. 11 em of plant available water are stor.ed in the profile to a depth of 90 em.

PHYSICAL CHARACTERISTICS (i) The soil surface sets hard after rain when not protected by vegetation.

GRIIIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE PAS'IVHE IMPROVED SOJ.IN PASTURE

USE SUITABILITY s s s s

N and P after N and P after FERTILIZER REQUIREMENTS continuous continuous NP NP cultivation cultivation

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, paspalum, medics (where pH> 6.5) and white clover in climatic zones Al, A2

and B. Fescue, phalaris and kikuyu (if N is applied) in Aland A2. Lucerne in A2 and B.

Creeping blue grass, Kazungula Setaria and Siratro in B.

PASTURE CARRYING CAPACITY (i) Native 2.4

( ha/beast) (ii) Improved 1.4

RUNOFF CONTROL STRUCTURES (i) Contour banks NBCB

( i i) Waterways s

(e) Grass species Kikuyu, Rhodes grass, Indian blue grass

(b) Fertilizer N,P

(iii) Diversion and pondage banks

MAXIMUM PERMISSIBLE VELOCITY (i) Bare earth channel 0.6 m/sec

(ii) Grassed waterway channel 1.2 m/sec

(iii) Diversion bank channel .0 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY A

DRAINAGE DESIGN RATING 8.0

SOIL ERODIBlllT'1 (K factor) 0.25

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION 10%

UPPER LAND SLOPE LIMIT FOR TREE CLEARING ND

LAND CAPABILITY CLASSIFICATION III VI e3-6, m2, n2 11-14

11.2 BASALT WEST LAND RESOURCE AREA 11-15

BASALT WEST LAND RESOURCE AREA

Mapping Symbol - Ke

SOIL NUTRIENT STATUS High

SURFACE pH 6.5 7.0

PLANT AVAILABLE WATER CAPACITY Very 1 ow

PHYSICAL CHARACTERISTICS (i) S-hallow soil depth

(ii) Large amounts of stone and rock on the SLirface and throughout the profile.

GFAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE PASTURE IMPROVED SOW/Jl PASTURE

USE SUITABILITY NS NS NS NS s

FERTILIZER REQUIREMENTS p .s

SUITABLE IMPROVED PASTURE SPECIES Green panic, Rhodes grass, creeping blue grass, medics and lucerne (This AMU only occurs in clil'laticzone C)

PASTURE CARRYING CAPACITY {i) Native 2.4

(ha/beast} {ii) Improved

RUNOFF CONTROL STRUCTURES {i) Contour banks NS

(ii) Waterways NS

(a) Grass species

(b) Fertilizer

(iii) Diversion and Pondage banks

MAXIMUM PERMISSIBLE VELOCITY (i) Bare earth channel NA

(ii} Grassed waterway chaline1

(iii) Diversion bank channel NA

RUNOFF COEFFICIENT SOIL CATEGORY

DRAINAGE DESIGN RATING NA

SOIL ERODIBILITY (K factor) 0.26

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION NS

UPPER LAND SLOPE LIMIT FOR TREE CLEARING - 17 - 20% (interim)

LAND CAPABILITY CLASSIFICATION VI e4-6, m3, d4-6, r3-5

OTHER INFORMATION (i) In certain locations, grassed areas of this unit provide valuable water dispersal areas for

contour banks from adjoining cultivation and eliminate the need for waterways.

(ii) Because of steepness and stoniness.pasture seed cannot be drilled and must be broadcast. 11-16

BASALT WEST LAND RESOURCE AREA

PURRA!jUNDA AMU

Mapping Symbol - Pu.c

SOIL NUTRIENT STATUS High

SURFACE pH 7.5

PLANT AVAILABLE WATER CAPACITY Moderate but depends on soil depth to decomposing basalt. A profile with a decomposing basalt

layer at 6Q em will hohi between 9 and 12 em of plant available water to that depth .

PHYSICAL CHARACTERISTICS (i) StrOng medium granular structure

{ii) Cracking

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/HNE CROPS NATIVE PASTURE IMPROVED SOWN PP.STURE

USE SUITABILITY s LS NS s s

N and P after and P after FERTILIZER REQUIREMENTS continuous continuous P,S cultivation cultivation

SUITABLE IMPROVED PASTURE SPECIES Green panic, Makarikari grass (cv. Bambatsi), Rhodes grass, lucerne and medics (This AMU only

occurs in climatic zone C).

PASTURE CARRYING CAPACITY (i) Native 2.4

{hajbeast) ( ii) Improved NA

RUNOFF CONTROL STRUCTURES (i) Contour banks BBTS

(ii) Waterways s

(e) Grass species Kikuyu, African star grass, Indian blue grass

(b) Fertilizer N

(o) Construction technique Standard

(iii) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel 0.5 m/sec

(ii) Grassed waterway channel 1.2 mjsec

(iii) Diversion bank channel 1.0 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY B

DRAINAGE DESIGN RATING 6.8

SOIL ERODIBILITY (K factor) 0.38

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION 8%

UPPER LAND SLOPE LIMIT FOR TREE CLEARING 17-20% (interim)

LAND CAPABILITY CLASSIFICATION II - IV e2-4

01HER 1NFORMA11DN (i) lhe deep phase of this soll (> 75 mm) may occur in association with the Irving clay and is

regarded as having the same limitations and management requirements as the Irving AMU.

(ii) Stubble mulching and/or minimum tillage are recommended to reduce soil erosion. 11-17

11.3 BASALT EAST LAND RESOURCE AREA 11-18

BASALT EAST LAND RESOURCE AREA

BFs AND BSs AI'U'

Mapping Symbol - BFs and BSs

SOIL NUTRIENT STATUS High. Nitrogen is high. Phosphorus is high to very high. ,Potassium is marginal to adequate.

SURFACE pH 6. 5 7.0

PLANT AVAILABLE WATER CAPACITY - Very low

PHYSICAL C\-lA.RACTERlSTlCS li) Shallow soil depth

(ii) Large amounts of stone and rock throughout the profile

GBAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE PASTURE II1PROv:ED SOWN PASTURE

USE SUITABILITY NS NS NS NS s s

FERTILIZER REQUIREMENTS N ,P ,S

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, green panic, paspalum, Kazungula Setaria, creeping blue grass, white clover,

Siratro and medics (This AMU only occurs in climatic zone B).

PASTURE CARRYING CAPACITY lil Native 2.0 - 2.4

(ha/beast) ( i i) Improved 1.2 - 1.6

RUNOFF CONTROL STRUCTURES (i) Contour banks NS

( ii) Waterways NS

lo) Grass species

Ib) Fertilizer

lei Construction technique

(iii) Diversion and pondage banks

MAXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel NA

( ii) Grassed waterway channel NA

(iii) Diversion bank channel NA

RUNOFF COEFFICIENT SOIL CATEGORY 8

DRAINAGE DESIGN RA1ltffi NA

SOIL ERODIBILITY (K factor) 0.26

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION NA

UPPER LAND SLOPE LIMIT FOR TREE CLEARING 17 20% (interim)

LAND CAPABILITY CLASSIFICATION VI - VII e6, m3, d4-6, r4-S, t6-7

OTHER INFORMATION Iii Because of steepness and stoniness,seed cannot be drilled and must be broadcast. 11-19

BASALT EAST LAND RESOURCE AREA

BSn A14U

Mapping Symbol - BSd

SOIL NUTRIENT STATUS High. Nitrogen is initially high. Phosphorus is very high. Potassium is adequate. This soil often occurs

in complexes with sandstone derived soils of low nutrient status.

SURFACE pH 6.5

PLANT AVAILABLE WATER CAPACITY Moderate to high but depends on soil depth. The plant available water capacity for a profile

to a depth of 90 em would vary from 14 to 19 em.

PHYSICAL CHARACTERISTICS (i) Well structured surface

(ii) Cracking soil

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE PASTURE IMPROVED SOWN PASTURE

USE SUITABILITY s s LS NS s

FERTILIZER REQUIREMENTS NP NP N,P,S

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, green panlC, paspalum, Kazungula Setaria, creeping blue grass, white clover,

Siratro, medics and lucerne (This AMU only occurs in climatic zone B).

PASTURE CARRYING CAPACITY (i) Native 2.0 - 2.4

(ha/beast) (ii) Improved 1.2 1.6

RUNOFF CONTROL STRUCTURES (i) Contour banks NBCB (some soil cracking does occur)

(ii) Waterways

1•1 Grass species Kikuyu, African star 9rass, Rhodes grass, Indian blue grass

(b) Fertil-izer N

(o) Construction technique Standard

(iii) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel 0.5 m/sec

(ii) Grassed waterway channel 1.2 m/sec

(; i i) Diversion bank channel 1.0 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY

DRAINAGE DESIGN RATING 6.8

SOIL ERODIBILITY (K factor) 0.36

UPPER LAND SLOPE LIMIT FOR PE�MP_NP!T CULTIVATION - 8%

UPPER LAND SLOPE LIMIT FOR TREE CLEARING 17 20% (interim)

LAND CAPABILITY CLASSIFICATION III VI e3-6

OTHER INFORMATION (i) Stubble mulching and/or minimum tillage are recommended to reduce soil erosion. BASALT EAST LAND RESOURCE AREA

BFn AMU

�lapping Symbol - BFd

SOIL NUTRIENT STATUS High. Nitrogen is fair. Phosphorus is high. Potassillm is adequate.

SURFACE pH 6.5 7.0

PLANT AVAILABLE WATER CAPACITY Moderate to high but depends on soil depth. The plant available water capacity for a profile

to a depth of 90 em would vary from 14 to 19 em. Moisture stress will occur in the shallow phase.

PHYSICAL CHARACTERISTICS (i) Strongly structured surface (ii) Crac.�ing

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE PASTURE IMPROVED SOf!N PASTURE

USE SUITABILITY s s LS NS s s

FERTILIZER REQUIREMENTS NP NP N ,P ,S

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, green panic, paspalum, Kazungula Setaria, creeping blue grass, while clover,

Siratro, medics and lucerne (This AMU only occurs in climatic zone B).

PASTURE CARRYING CAPACITY (i) Native 2.0 - 2.4

(ha/beast) ( i i) Improved 1.2 - 1.6

RUNOFF CONTROL STRUCTURES (i) Contour banks - NBCB (some soil cracking does occur)

('ii) Waterways 5

(,) Grass species Kikuyu, African star grass, Rhodes grass, Indian blue grass

I b) Ferti 1 i zer N

(iii) Diversion and pondage banks 5

MAXIMUM PERMISSIBLE VELOCITY - ( i) Bare earth channel 0.5 m;sec

(ii) Grassed waterway channel 1.2 m/sec

(iii) Diversion bank channel 1.0 m/sec

RUNOFF COEFFICIE

DRAINAGE DESIGN RATING 6.8

SOIL ERODIBILITY (K factor) 0.38

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION 8%

UPPER LAND SLOPE LIMIT FOR TREE CLEARING 17 20% (interim)

LAND CAPABILITY CLASSIFICATION III -VI e3-6

OTHER INFORMATION (i) Stubble mulching and minimum tillage are recommended to reduce inter bank erosion. 11-21

BASALT EAST LAND RESOURCE AREA

BFwn AMU

Mapping Symbol - BFwd

SOIL NUTRIENT STATUS Moderately high. Nitrogen is fair to high. Phosphorus is very high. Potassium is adequate.

SURFACE pH 6.5

PLANT AVAILABLE WATER CAPACITY Moderate to high but depends on soil depth. The plant available water capacity for a profile to a

dept\'1 of 90 em would vary from 14 to 19 Clll.

PHYSICAL CHARACTERISTICS (i) Surface structure deteriorates with Continuous cultivation.

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIV!l' PASTURE IMPROVED SOWN PASTURE

USE SUITABILITY s s LS NS s

FERTILIZER REQUIREMENTS NPS NPS NPS

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, paspalum, creeping blue grass, Kazungula Setaria, white clover, lucerne,

Siratro and medics.

PASTURE CARRYING CAPACITY (i) Native 2.0 2.4

{ha/beast) (ii) Improved 1.2 - 1.6

RUNOFF CONTROL STRUCTURES (i) Contour banks NBCB

(ii) Waterways s

(e) Grass species Kikuyu, African star grass, Rhodes grass, Indian blue grass

(b) Fertilizer N

{iii) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY - {i) Bare earth channel 0 5 m/sec

{i i) Grassed waterway channel 1.2 m/sec

(iii) Diversion bank channel 0 mjsec

RlJNOFF CQE.FFlClENi SOil CATEGORY B

DRAINAGE DESIGN RATING 6.8

SOIL ERODIBILITY (K factor) 0.38

UPPER LAND SLOPE LIMIT FOR PERt·1ANENT CULTIVATION - 8%

UPPER LAND SLOPE LIMIT FOR TREE CLEARING 17 - 20% (interim)

LAND CAPABILITY CLASSIFICATION III VI e3-6, m2, p2, dl-2

01HER INFORMATION (i) A crop rotation system which includes a pasture ley is recommended to maintain surface

soi 1 structure.

{ii) Stubble mulching and/or minimum tillage are recoTmJended to reduce interbank erosion. 11-22

11.4 BASALTIC RED SOILS LAND RESOURCE AREA BASAL TIC RED SOILS LAND RESOURCE AREA

CABARLAH AMU

Mapping Symbol Cab

SOIL NUTRIENT STATUS Very low.

SURFACE pH 5.8

PLANT AVAILABLE WATER CAPACITY Low.

PHYSICAL CHARACTERISTICS (i) Shallow soil depth

(ii) Stone and gravel on the surface and throughout the profile

(iii) Soil surface is moderately weak to structureless

( iv} Well drained soil

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE PASTURE IMPROVED SOWN PASTURE

USE SUITABILITY NS NS NS NS s s

FERTILIZER REQUIREMENTS N, P ,S Mo every 5 years

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass and paspalum in all climatic zones. White clover in zones Al, A2 and B. Kikuyu,

phalaris and fescue in zones Al and A2. Kazungula Setaria in zone B. Siratro and creeping

blue grass in zones B and C.

PASTURE CARRYING CAPACITY (i) Native 1.1 2.4 (ha/beast} ( ii} Improved 0.7 - 1.2

RUNOFF CONTROL STRUCTURES (i) Contour banks NS

(ii) Modified contour banks/beds NS

(iii) Waterways NS

(,) Grass species NA

(b) Fertilizer NA

( iv) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel NA

(ii) Grassed waterway channel NA

RUNOFF COEFFICIENT SOIL CATEGORY B

DRAINAGE DESIGN RATING NA

SOIL ERODIBILITY (K factor) 0.26

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION NS

UPPER LAND SLOPE LIMIT FOR TREE CLEARING 17- 20% (interim)

LAND CAPABILITY CLASSIFICATION V - VI e3-6, m4, n3, d4-6, r3-5

OTHER INFORMATION (i) Because of stoniness, pasture seed cannot be drilled and must be broadcast. 11-24

BASALTIC RED SOILS LAND RESOURCE AREA

PECHEY A'1U

Mapping Symbol Pey

SOIL NUTRIENT STATUS Low. Nitrogen is initially moderate but decreases rapidly with cultivation. Phosphorus is low.

Potassium is low to fair.

SURFACE pH 6.2

PLANT AVAILABLE WATER CAPACITY Modero.te to high.

PHYSICAL CHARACTERISTICS (i) Well drained soil

{ii) Soil surface is structureless (snuffy)

{iii) - Rainfall is initially absorbed very slowly

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE PASTURE Il1PROVED SOWN PASTURE

USE SUITABILITY LS s s s

FERTILIZER REQUIREMENTS NPK NPK NPS Mo every 5 years.

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass and paspalum in all climatic zones. White clover in zones Al, A2 and B.

Kikuyu, phalaris and fescue in zones A1 and A2. Lucerne in zonesA2. B and c. Kazungula

Setaria in zone B. Siratro and creepin') blue grass in zones B and C.

PASTURE CARRYING CAPACITY (i) Native 1.1 - 2.4

( ha/beast) {ii) Improved 0. 7 - 1. 2

RUNOFF CONTROL STRUCTURES (i) Contour banks NBCB

( ii) Modified contour banks/beds s

(iii) Waterways s -

(<) Grass species Kikuyu, Rhodes grass, Indian blue grass

(b) Fertilizer N,P ,K

after excavation.

(iv) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY - ( i) Bare earth channel 0.6 m/sec

(ii) Grassed waterway channel 1.2 m/sec

(iii) Diversion bank channel 0.8 mjsec

RUNOFF COEFFICIENT SOIL CATEGORY B

DRAINAGE DESIGN RATING 8.0

SOIL ERODIBILITY (K factor) 0.26-

UPPER LAND SLOPE LIMIT FOR PEP�'.IlNENT CULTH�TON 8% UPPER LAND SLOPE LIMIT FOR TREE CLEARING 17 - 20% (interim)

LAND CAPABILITY CLASSIFICATION III IV e2-4, m2, n2, p2

OTHER INFORMATION (i) The use of nitrogenous fertilizer on dairy pastures in climatic zone A can be an

economic practice.

{ii) Rolling is recommended for pasture establishment. 11-25

PALmREE AMU

Mapping Symbol - Pal

SOIL NUTRIENT STATUS Nitrogen is initially high but decreases rapidly with cultivation. Potassium is generally adequate.

Phosphorus is variable and varies from fair to high.

SURFACE pH 5.8

PLANT AVAILABLE WATER CAPACITY Moderate to high

PHYSICAL CHARACTE Rl S TICS (i) Internal drainage is slow below 60 em

{ii) Moderate surface structure

GRAIN CROPPING FODDER CROPPING SMALL CROPS THEE/VINE CROPS NATIVE PASTURE fl1PROVED SOWN PASTURE

USE SUITABILITY LS s s s (suitable for 1 imited winter)

FERTILIZER REQUIREMENTS NP NP N,P,S Mo every 5 years

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, pas palum and green panic in all climatic zones. ��hite clover in zones Al, A2 and

B. Kikuyu, phalaris and fescue in zones Al and A2. Lucerne in zones A2, 8 and C. Kazungula

Setaria in zone B. Siratro and creeping blue grass in .zones Band C'.

PASTURE CARRYING CAPACITY (i) Native 1 - 2.4 {ha./beast) (i i) Improved 0.7 - 1.2

RUNOFF CONTROL STRUCTURES (i) Contour banks NBCB

( i i) Modified contour banks/beds s

(iii) Waterways s

1,1 Grass species Kikuyu, Rhodes grass, Indian blue grass

(b) Fertilizer N,P ,K

after excavation.

( iv) Diversion and pondage banks

MAXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel 0.6 m/sec

( j i) Grassed waterway channe1 1.2 m/sec

(iii) Diversion bank channel 0.8 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY A

DRAINAGE DESIGN RATING 8.0

SOIL ERODIBILITY (K factor) 0.24

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION 10%

UPPER LAND SLDPE LIMIT FOR TREE CLEARING 17 20% (interim)

LAND CAPABILITY CLASSIFICATION III VI e3-6, m2, nl-2

OTHER INFORMATION {i) The use of nitrogenous fertilizer on dairy pastures in climatic zone A can be an economic practice. 11-26

BASALTIC RED SOILS LAND RESOURCE AREA

GEHAfl .�MU

Mapping Symbol Geh

SOIL NUTRIENT STATUS Low. Nitrogen is initially fair but declines rapidly with cultivation. Potassium is low to adequate.

Phosphorus is very low.

SURFII.CE pH 6.2

PLANT AVAILABLE WATER CAPACITY Moderate.

PHYSICAL CHARACTERISTICS (i) Subsoil is slowly penneable

(ii) Perched watertable may be present

GRAIN CROPPING FODDER CROPPING S/1ALL CROPS TREE/VINE CROPS NATIVE PASTURE IMPROVED SOWN PASTURE

USE SUITABILITY LS s LS NS s (due to impeded drainage)

FERTILIZER REQUIREMENTS NPK NPK NPS Mo every 5 years.

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass and paspalum in all climatic zones. \�hite clover in zones Al, A2 and B. Kikuyu,

phalaris and fescue in zones Al and A2. Lucerne in zones A2, B and C. Kazungula Setaria

in zone B. Siratro and creeping blue grass in zones B and C.

PASTURE CARRYING CAPACITY (i) Native 1.1 2.4 ( ha/beast) (ii) Improved 0.7 - 1.2

RUNOFF CONTROL STRUCTURES (i) Contour banks NBCB

(i;) Modified contour banks/beds

{iii) waterways

(a) Grass species Kikuyu, Rhodes grass, Indian blue grass

(b) Fertilizer N, P ,K

(ol Construction technique Either constructed from the outside or topsoil replaced

after excavation.

(iv) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY (i) Bare earth channel 0. 5 m/sec

{ii) Grassed waterway channel 1.2 mjsec

(iii) Diversion bank channel 0 .8 m/sec

RUNOFF COEFF1CIENI SOil CA1EGORY B

DRAINAGE DESIGN RATING 8.0

SOIL ERODIBILITY (K factor) 0.25

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION 8%

UPPER lAND SLOPE LIMIT FOR TREE CLEARING 17 - 20% (interim)

LAND CAPABILIIY CLASSIFICATION III IV e2-4, m2, n2, p2

OIHER INFORMATION ( ;) Roll in� is recommended for pasture establishment

(ii) The use of nitrogenous fertilizer on dairy pastures in climatic zone A can be an

economic practice. 11-27

BASALTIC RED SOILS LAND RESOURCE AREA

RAVENSBOURNE P.MU

Mapping Sjffllbol Rav

SOIL NUTRIENT STATUS �loderate. Nitr ogen is initially very high. Phosphorus is generally low but variable. Potassium is adequate.

SURFACE pH 5.5

PLANT AVAILABLE WATER CAPACITY 11odera te to high.

PHYSICAL CHARACTERISTICS (i) Very well drained, deep soil

( i i) Moderate surface structure

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATXVE PASTURE IMPROVED S0\>1/1 PASTURE

USE SUITABILITY s s s s s s

FERTILIZER REQUIREI�ENTS NP NP NP Mo every 5 years

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass. paspalum and green panic in all climatic zones. White clover in zonesAl, A2 and B.

Kikuyu, phalaris and fescue in zones Al and A2. Lucerne in zones A2, B and C. Kazungula

Setaria in zone B. Siratro and creeping blue grass in zones B and C.

PASTURE CARRYING CAPACITY (i) Native {hajbeast) ( i i) Improved 0.7 - 1.1

RUNOFf CONTROL STRUCTURES \i) Contour banks NBCB

(ii) Modified contour banks/beds

(iii) Waterways s

(<) Grass species Kikuyu, Rhodes grass, Indian blue grass

(b) Fertilizer N,P ,K

(o) Construction technique Either constructed from the outside or topsoil replaced

after excavation.

(iv) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel 0.6 mjsec

( ii) Grassed water;vay channel 1.2 m/sec

(iii) Diversion bank channel 0.8m/sec

RUNOFF COEFFICIENT SOIL CATEGORY A

DRAINAGE DESIGN RATING 8.6

SOIL ERODIBILITY {K factor) 0.24

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION 10%

UPPER LAND SLOPE LIMIT FOR TREE CLEARING 17 - 20% (interim)

LAND CAPABILITY CLASSIFICATION IV - VI e4-6, mZ, nl-2

OTHER INFORMATION The use of nitrogenous fertilizer on dairy pastures in climatic zone A can be an economic practice. 11-28

BASAL TIC RED SOILS LAND RESOURCE AREA

PINELANDS 1 AND 2 AMU s

Mapping Symbol - Pin

SOIL NUTRIENT STATUS (i) Pinelands 1 - Nitrogen is initially high. Phosphorus is very high. Potassim is adequate

to high.

{ii) Pinelands 2 - Nitrogen is fair. Phosphorus is very high. Potassium is deficient to

marginal.

SURFACE pH (i) Pinel ands 7.2

(ii) Pine lands 5.0

PLANT AVAILABLE WATER CAPACITY High

PHYSICAL CHARACTERISTICS (i) Pinelands 1 (a) Well structured surface

(b) Stone occurs throughout the profile

(ii) Pinelands 2 - {a) Surface is structureless

GRAIN CROPPING FODDER CROPPING SM/,LL CROPS TREF;/VINE CROPS NATIVE PASTURE IMI?FIOVED SOWN PASTURE

USE SUITABILITY LS s s s s

FERTILIZER REQUIREMENTS NP NP NP

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, paspalum, green panic and creeping blue grass in all zones. White clover in

zones Al, AZ and B. Kikuyu, phalaris and fescue in zones Aland AZ. Lucerne in zones AZ,

B, C. Kazungula Setaria in zone B. Siratro in zones B and C.

PASTURE CARRYING CAPACITY (i) Native

(ha/beast) (i i) Improved 0. 7 - 1.1

RUNOFF CONTROL STRUCTURES (i) Contour banks - rJBGB

(ii) Modified contour banks/beds s

(iii) Waterways

(o) Grass species Kikuyu, Rhodes \)rass, Indian blue grass

(b) Ferti1izer N,P,K

I c) Construction technique Either constructed from the outside or topsoil replaced

after excavation.

(iv) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel 0.6 m/sec

(ii) Grassed waterway channel 1.2 m/sec

(iii) Grassed diversion bank channel 0.8 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY f;

DRAINAGE DESIGN RATING 8.6

SOIL ERODIBILITY (K factor) 0.24

UPPER LAND SLOPE LIMIT FOR PERtlANENT CULTIVATION - 10%

UPPER LAND SLOPE LIMIT FOR TREE CLEARING 17 - 20% (interim)

LAND CAPABILITY CLASSIFICATION IV - VI e4-6, m2, nl-2 11-29

BASAL TIC RED SOILS LAND RESOURCE AREA

�1ERRITTS Ai'1U

Mapping Symbol � Mer

SOIL NUTRIENT STATUS Nitrogen is initially high. Phosphorus is fair to high. Potassium is generally adequate. Responses to

molybdenum and sulphur have been reported.

SURFACE pH 5.8

PLANT AVAILABLE WATER CAPACITY Moderate

PHYSICAL CHARACTERISTICS (i) Well structured surface

( ii} Cracking

GRAIN CROP?ING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NA TIVE PASTURE IMPROVED SOWN PASTURE

USE SUITABILITY s LS NS

FERTILIZER REQUIREI�ENTS NP NP N,P,S Mo every 5 years

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, p""spalum and medics in all climatic zones. White clover is zones Al, A2 and B.

Kikuyu, phahris and fescue in zones Al and A2. Lucerne in zones A2, B and C. Kazungula

Setaria in zone B. Siratro and creeping blue grass in zones B and C.

PASTURE CARRYING CAPACITY (i) Native 1.1 - 4

( hajbeast) ( il) lmproved 0. 7 l.2

RUNOFF CONTROL STRUCTURES (i) Contour banks NBCB (even though some soil cracking occurs)

(ii) Modified contour banks/beds s

(;; i) Waterways s

(e) Grass species Kikuyu, Rhodes grass, Indian blue grass

(b) Fertilizer N, P,K

(iv) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel 0.5 m/sec

(i i) Grassed waterway channel 1.2 mjsec

(iii) Diversion bank channel 0.8 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY B

DRAINAGE DESIGN RATING 6.8

SOIL ERODIBILITY (K factor) 0.36

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTlVATION 8%

UPPER LI\ND SLOPE LIMIT FOR TREE CLEARING 17 - 20% {interim)

LAND CAPABILITY CLASSIFlCATION III VI e3-6, nl-2

OTHER IN�'"ORMATION {i) The use of nitrogenous fertilizer on dairy pastures in climatic zone A can be an

economic practice. 11-30

11.5 ALLUVIUM LAND RESOURCE AREA 11-.)1

ALLUVIUM LAND RESOURCE AREA

WACO AI'U

SOIL NUTRIENT STATUS Very high

SURFACE pH - 7.5

PLANT AVAILABLE WATER CAPACITY High. The plant available water capacity of a pro,file to a depth of 90 em would

approximate 20 em.

PHYSICAL CHARACTERISTICS - (i) Self mulching

(ii) Cracking

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE PASTURE IMPROVED SOWN PASTURE

USE SUITABILITY 5 LS NS s s

N and P N and P FERTILIZER REQUIREMENTS after continuous after continuous cultivation cultivation

SUITABLE IMPROVED PASTURE SPECIES - Rhodes grass, green panic, creeping blue grass, Makarikari grass (cv. Bambatsi),

Columbus grass, lucerne, Jemalong barrel and snail medics.

PASTURE CARRYING CAPACITY - (i) Native NA

(ii) Improved NA

RUNOFF CONTROL STRUCTURE-S - (i) Contour banks s

(ii) Waterways s

(o) Grass species Kikuyu, African star grass, Indian blue grass

(b) Fertilizer NP

(iii) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel 0.5 mjsec

( ii) Grassed waterway channel 1.2 m/sec

(iii) Diversion bank channel 0.8 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY - B

DRAINAGE DESIGN RATING -

SOIL ERODIBILITY (K factor )

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION - NA

UPPER l!I.NO SLOPE LIMIT fOR 1REE CLEJ\RlNG - Nil.

LAND CAPABILITY CLASSIFICA110N - I - II el-2 11-32

ALLUVIUM LAND RESOURCE AREA

ALS AMU

SOIL NUTRIENT STATUS Moderate

SURFACE pH - 6.0- 7.0

PLANT AVAILABLE WATER CAPACITY Moderate to high - approximately 15 em of plant available water are stored in the

profi 1 e to a depth of 90 em.

PHYSICAL CHARACTERISTICS - Iii' Strong fine surface structure

( i i) Cracking

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/V DIE CROPS NATIVE PASTURE IMPROVED SOWN PASTU'RE

USE SUITABILITY s LS HS s s

N and N and FERTILIZER REQUIREMENTS after continuous after continuous p cultivation cultivation

SUITABLE IMPROVED PASTURE SPECIES - Rhodes grass, green panic, paspalum, creeping blue grass, kikuyu (in favourable areas),

white clover, lucerne and medics.

PASTURE CARRYING CAPACITY - (i) Native

(ii) Improved NA

RUNOFF CONTROL STRUCTURES - (i) Contour banks s

( i i) Waterways s

(o) Grass species African star grass, kikuyu, Indian blue grass

(b) Fertilizer NP

(iii) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel 0.5 m/sec

(ii) Grassed waterway channel 1.2 m/sec

(iii) Diversion bank channel 0.8 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY B

DRAINAGE DESIGN RATING

SOIL ERODIBILITY (K factor)

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION NA

UPPER LAND SLOPE LIMil FOR TREE CLEARING NA

LAND CAPABILITY CLASSIFICATION I - II el-2 11-33

ALLUVIUM LAND RESOURCE AREA

ALW AMU

SOIL NUTRIENT STATUS Moderate

SURFACE pH - 6. 5

PLANT AVAILABLE WATER CAPACITY Moderate. Approximately 11 em of plant available water are stored in the profile

to a depth of 90 em.

PHYSICAL CHARACTERISTICS - (i) Weak surface structure

(ii) Surface crusting

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE PASTURE IMPROVED SOWN PASTURE

USE SUITABILITY 5 LS NS s s

FERTILIZER REQUIREMENTS NP NP

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, green panic, paspalum, creeping blue grass, kikuyu (in favourable areas), white

clover and lucerne.

PASTURE CARRYING CAPACITY - (i) Native - NA

( ii) Improved - NA

RUNOFF CONTROL STRUCTURES - (i) Contour banks s

( i i) Waterways s

(') Grass species African star grass, kikuyu, Rhodes grass, Indian blue grass

(b) Fertilizer NPK

(o) Construction technique standard

(iii) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel 0.5 m/sec (ii) Grassed waterway channel 1.2 m/sec

(iii) Diversion bank channel 0.8 mjsec

RUNOFF COEFFICIENT SOIL CATEGORY

DRAINAGE DESIGN RATING

SOIL ERODIBILITY (K factor)

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION NA

UPPER LAND SLOPE LIMIT FOR TREE CLEARING NA

LAND CAPAB ILITY CLASSIFICATION II ei-2, p2 11-34

ALLUVIUM LAND RESOURCE AREA

ALH ��u

SOIL NUTRIENT STATUS Low to moderate.

SURFACE pH 5.5 to 6.0

PLANT AVAILABLE WATER CAPACITY Low to moderate - approximately 8 em of plant available water are stored in the profile

to a depth of 60 ern.

PHYSICAL CHARACTERISTICS The soil surface sets hard.

GRAIN CROPPING FODDER CROPPING SMALL CROPS TREE/VINE CROPS NATIVE PASTURE IMPROVED SOWN PASTURE

USE SUITABILITY s s LS NS s

FERTILIZER REQUIREMENTS NP NP p

SUITABLE IMPROVED PASTURE SPECIES Rhodes grass, creeping blue grass, paspalum, medics, lucerne, white clover, Siratro.

PASTURE CARRYING CAPACITY (i) Native 2.4

(ha/beast) (ii) Improved 1.4

RUNOFF CONTROL STRUCTURES (i) Contour banks s

(ii) Waterways

(o) Grass species African star grass, kikuyu (with extra N), Rhodes grass,

Indian blue grass

(b) Fertilizer N,P,K

(iii) Diversion and pondage banks s

MAXIMUM PERMISSIBLE VELOCITY - (i) Bare earth channel 0 5 m/sec

(ii) Grassed waterway channel 1.2 m/sec

(iii) Diversion bank channel 0.8 m/sec

RUNOFF COEFFICIENT SOIL CATEGORY B

DRAINAGE DESIGN RATING

SOIL ERODIBILITY (K factor)

UPPER LAND SLOPE LIMIT FOR PERMANENT CULTIVATION NA

UPPER LAND SLOPE LIMIT FOR TREE CLEARING NA

LAND CAPABILITY CLASSIFICATION rrr el-2, m2, n2, p2 12-1

BIBLIOGRAPHY

Anon. - Soil Conservation Handbook, Queensland. Soil Conservation Branch, Qd Dep. Prim. Inds.

Bierenbroodspot, J. (1967) -Water spreading on pastures. Qd Agrie. J. 93:259-61.

Bierenbroodspot, J. (1972) -Contour banks and erosion. Qd Agrie. J. 98:259-60.

Cranfield, L.C. , Schwarzbock, H. and Day, R.W. (1976) -The geology of the Ipswich and Brisbane 1:250 000 sheet areas. Geological Survey of Queensland No. 95.

Cull, J. (1972) - "Crow' s Nest Shire Handbook". Qd Dep. Prim. Inds., Brisbane.

Holmes, K.H. (1981) - Land stability on the eastern slopes of Toowoomba. Geological Survey of Queensland. Record Series.

Lehmann, G.M. and Bartels, H. (1978a) - Build your contour banks with a farm dozer. Soil Conservation Branch, Qd Dep. Prim. Inds.

Lehmann, G.M. and Bartels, H. (1978b) - Build your waterways with a farm dozer. Soil Conservation Branch, Qd Dep. Prim. Inds.

Marshall, J., Mullins, J., Freebairn, D., Donnollan, T., Glanville, S. and Crothers, R. (1980) - Erosion survey for the Clifton, Cambooya and Pittsworth Shires eastern Darling Downs after the storm events of the 26.1.80 to 5.2.80. Teeh. Report Div. Ld Util. Qd Dep. Prim. Inds. No. 80/15.

Mullins, J.A. (1977) - The dispersion test. Teehnieal Nevs SoiZ Conservation Darling Dovns Region 1:14-15.

Mullins, J.A. (1978) -Description and management of the soils of the eastern Darling Downs, Queensland. Teeh. BuZZ . Div. Ld UtiZ. Qd Dep. Prim. Inds. No. 33.

Murphy, P.R., Schwarzbock, H., Cranfield, L.C., Withnall, I.W. and

Murray, C.G. (1976) - Geology of the Gympie 1:250 000 sheet area. Geological Survey of Queensland No. 96.

Nevell, P.P., Truong, P.N. and Turner, E.J. (1981) - Conservation grazing management. Teeh. Report Div. Ld UtiZ. Qd Dep. Prim. Inds. No. 81/1. 12-2

Rosenthal, K.M. and White, B.J. (1980) - Distribution of a rainfall erosion index in Queensland. Tech. Report Div. Ld Util. Qd Dep. Prim. Inds. No. 80/8.

Rosser, J., Swartz, G.L., Dawson, N.M. and Briggs, H.S. (1974) - A land capability classification for agricultural purposes. Tech. Bull. Div. Ld Util. Qd Dep. Prim. Inds. No. 14.

Thompson, C.H. and Beckmann, G.G. (1959) - Soils and land use in the Toowoomba area, Darling Downs, Queensland. Soils Ld Use Series CSIRO Aust. No. 28.

Truong, P.N. (1979) - The Ellinbank Pasture Meter - a new method for measuring retardance categories in grassed waterways. Tech. News Div. Ld Util. 3:30-32.

Truong, P.N. and McDowell, M.G. (1980) - Monitoring grass retardance categories in waterways with an Ellinbank Pasture Meter. Tech. News Div. Ld Util. 4:38-42.

USDA (1954) - Handbook of channel design for soil and water conservation. Stillwater Outdoor Hydraulic Laboratory, Stillwater Oklahoma. Soil Conservation Service - TP - 61 Washington D.C.

Vandersee, B.E. (1977) - Field identification of impermeable B horizons of the Marburg Formation soils. Technical News Soil Conservation Darling Downs Region 1:5-6.

Vandersee, B.E. and Mullins, J.A. (1977) - Land evaluation of representative areas of the Marburg Formation and the Poplar Box Walloons of the Eastern Downs Queensland. Tech. Bull. Div. Ld Util. Qd Dep. Prim. Inds. No. 21.

Wischmeier, W.H. and Smith, D.O. (1978) - Predicting rainfall erosion losses - a guide to conservation planning. Agric. Handb. U.S. Dep. Agric. No. 537. I-i

APPENDIX I

' Detailed Soils Information for the AMUs of the Basalt East.

Basaltic Red Soils and AI luvium Land Resource Areas

S.E. MACNISH

1. Soils in the relation to the landscaPe

2. Detailed Soil Profile DescriPtions

3. KeY to the AMUs of the Basalt East LRA

4. KeY to the AMUs of the Basaltic Red Soils LRA I-ii

1. Soils in Relation to the LandscaPe

The soils of the Basalt East and Basaltic Red Soils LRAs are developed on basalts and tuffaceous material respectively. The basalts are of Tertiary age (Miocene-Pliocene). Wo rk presently underway sugges ts that some of the tuffaceous material may be considerably younger (i.e. late Tertiary - Pleistocene age). The soils of the Alluvium LRA are formed on reworked material from the basalts and tuffs and in some cases mixed with or overlying coarse grained sediments predominantly of the Marburg Formation.

The Basalt East LRA includes all those cracking and non cracking dark clay soils formed on weathered basalt to the east and north east of the Great Dividing Range.

The Basaltic Red Soils LRA includes all those soils, predominantly krasnozems and associated colluvia, which have formed on the old Tertiary plateau surface or on its dissected remnants.

The Alluvium LRA consists largely of infilled trough valleys which interfinger all other LRAs in the district.

The distribution of soils in each of these three LRAs is directly controlled by geology and geomorphic processes. A brief outline of these relationships follows.

(i) Basalt East LRA

The basalts are of Tertiary age similar to the basalts of the Basalt West LRA. Uplift and dissection of the Main Range in this area in more recent times has, however, exposed fresh basalts on which weathering has proceeded for a comparatively shorter time than in the Basalt West LRA. This uplift and the subsequent deep dissection explains the relatively narrow and steep-sided valleys of the Basalt East LRA by comparison with landforms in the Basalt West LRA. The upper slopes are dominated by shallow skeletal soils and shallow gravelly clays. There is relatively poor development of colluvial soils in lower slope positions in the Basalt East LRA and valleys are characterised by trough valley infills instead. This indicates a process of rapid valley filling associated with uplift rather than a steady process of slope development by slope retreat and colluviation. In these situations, erosion often is restricted to deep incision of the valley floor, and the short slopes are frequently too steep for extensive agricultural use.

(ii) Basaltic Red Soils LRA

Soils in the Basaltic Red Soils LRA are developed both on deeply weathered basalts and on tuffaceous sediments. The soils formed depend largely on their position in the landscape. I-iii

Soils on plateau remnants and crests under open eucalypt forest are predominantly 'snuffy' krasnozems. Where these surfaces have been dissected, detrital or reworked ironstone-rich shallow krasnozems (Cabarlah AMU) have developed. Where sufficient colluvial material has collected on this upper dissected plateau surface, moderately deep cracking clays (Merritts AMU) have developed. These often tend to be in poorly drained depressions and may be associated with fluctuating watertables.

The Geham AMU, a xanthozem, is also developed in colluvial material derived largely from material from the Cabarlah and Pechey AMUs. It is associated with a fluctuating watertable and is generally impermeable by a depth of 45 em.

Deep earthy krasnozems (Ravensbourne AMU) dominate the rainforest and eucalypt open forest areas to the east and below the Main Range. These appear to have developed both on deeply weathered basalt and on tuffaceous material;. A shallower krasnozem (Palmtree AMU), which is generally impermeable by a depth of 60 em, occurs mainly in the transitional forest areas. This appears to be developed only on tuffaceous material.

The Pinelands 1 and 2 AMUs form a soil association that is controlled by local geology and have a restricted distribution in the north of the area. Pinelands 2 AMU, is a strongly acid soil which occurs on ridges, plateaux and steep valley sides and is developed on acid tuffaceous material. The Pinelands 1 AMU has developed on weathered basalt on benches in the landscape which occur at lower elevations than Pinelands 2. Pinelands 1 is thus a krasnozem on weathered basalt with colluvial additions of Pinelands 2 soil material.

(iii) Alluvium LRA

The three main alluvial soils are derived from varying rates of mixing of basaltic, tuffaceous and sandstone derived material. Three broad families of soils were defined.

Als AMU - these are strongly structured, self-mulching, cracking, black, clay soils derived predominantly from basaltic material.

Alw AMU - these are soils with crusting, poorly structured surfaces which are derived predominantly from basaltic material but with some Marburg Formation influence.

Alh AMU - these are hardsetting duplex soils which are derived predominantly from Marburg Formation material and have little or no basaltic influence. I-iv

2. Detai led Soi l Profi le Des criPt ions

Basalt East Land Resource Area

BSd Site 1

BSs Site 2

BFwd Site 5

BFs Site 6

BFd Site 8

Basaltic Red Soils LRA

Pinelands 2 Site 4

Ravensbourne Site 12

Palmtree Site 13

Pechey Site 15

Pinelands 1 Site 16

Merritts Site 17

Geham Site 18

Cabarlah Site 19

Alluvium LRA

Als Site 9

Alw Site 10

Alh Site 11 I-v

BASALT EAST LAND RESOURCE AREA

SUe

AGRICULTURAL MANAGEMENT UNIT: BSd PRINCIPAL PROFILE FORM (Northcote): Ug 5.13 DATE OF DESCRIPTION: 27th February, 1980 LOCATION: Craw's Nest District, Queensland 9243 1: 100 000 Sheet Number Australian Map Grid Reference 395500E 6987300N TOPOGRAPHY: Mid to lower slope position (10% land slope) on low, hilly terrain. PA�ENT HATERIAL: Tertiary basalt. PROFILE DRAINAGE: Moderately well drained. VEGETATION: Depauperate rainforest with Flindersia australis (Craw's Ash) and GreviZZea robusta (silky oak) and softwood scrub understorey. LAND USE: Selectively logged forest. MORPHOLOGY:

Depth (em) Description 0 - 2 Brownish black (7.5 YR 3/1 moist); self-mulching; medium-heavy clay; weak, very fine crumb; soft (dry). Field pH 6.5. Abrupt to -

2 - 10 Brownish black (7.5 YB 3.1 moist); heavy clay moderate, medium granular; slightly hard (dry} . Field pH 6.8. Clear to -

10 - 25 Brownish black (7.5 YR 3/1 moist); heavy clay; strong, medium granular; hard (dry). Field pH 7.2. Diffuse to -

25 - 40 Dark reddish brown (5 YB 3/2 moist); heavy clay; firm (moist). Trace of calcium carbonate nodules. Field pH 8.2. Diffuse to -

40 - 70 Grayish brown (5 YR 4/2 moist); heavy clay; firm (moist). Trace of calcium carbonate nodules and soft segregations. Field pH 8.5. Diffuse to -

70 - 80 Grayish brown (5 YR 4/2 moist); heavy clay; firm (moist). Small amount of soft calcium carbonate segregations and nodules. Field pH 9.5. Gradual to -

So - 120 Brown (7.5 YR 4/4 moist); medium clay; friable (moist). Small amount of soft calcium carbonate segregations and basaltic gravel. Field pH 9.5. I-vi

Sde 2

AGRICULTURAL MANAGEMENT UNIT: BSs PRINCIPAL PROFILE FORM ( Northcote) : Ug 5.12 DATE OF DESCRIPTION: 27th February, 1980 LOCATION : Craw's Nest District, Queensland 9243 1:100 000 Sheet Number Australian Map Grid Reference 397000E 6991900N TOPOGRAPHY: Upper convex slope position (15% land slope) on low, hilly terrain. PARENT HATERIAL: Tertiary basalt. PROFILE DRAINAGE: Well drained. VEGETATION: Depauperate rainforest with Flindersia australis (C raw's Ash) and Grevillea robusta (silky oak) and softwood scrub understorey.

LAND USE: Extensive logging and clearing for grazing. MORPHOLOGY:

Depth (em) Description

0 - 10 Brownish black (5 YR 3/l moist); self-mulching; light-medium clay; moderate, medium granular; hard (dry). Trace of basaltic gravel. Field pH 7.0. Gradual to -

10 - 20 Brownish black (5 YR 3/1 moist); light-medium clay; moderate, medium granular; hard (dry). Moderate amount of basaltic gravel. Field pH 7.0. Gradual to -

20 - 25 Brownish black (5 YR 3/l moist); light clay. Abundant basaltic gravel. Field pH 6.8.

Sde 5

AGRICULTURAL MANAGEMENT UNIT: BFwd PRINCIPAL PROFILE FORM ( Northcote) : Ug 5.13 DATE OF DESCRIPTION: 27th February, 1980 LOCATION: Craw's Nest District, Queensland 9243 1:100 000 Sheet Number Australian Map Grid Reference 379900E 7001200N TOPOGRAPHY: Mid to lower slope position (6 % land slope) on low, hilly terrain. PARENT MATERIAL: Tertiary basalt. PROFILE DRAINAGE: Moderately well drained. VEGETATION: Open woodland of Eucalyptus crebra (narrow-leaved ironbark) (cleared). LAND USE: Summer and winter dryland cropping. I-vii

MORPHOLOGY:

Depth (em) Description 0 - 10 Black (7.5 YR 2/l moist); self-mulching; light clay; weak, very fine crumb; soft (dry), very friable (moist). Trace of basaltic gravel. Field pH 6.5. Gradual to -

10 - 20 Black (7 .5 YR 2/l moist); light clay; weak, very fine crumb; soft (dry), friable (moist). Field pH 6. 8. Gradual to -

20 - 35 Dark reddish brown (5 YR 3/3 moist); light medium clay; weak, very fine blocky; soft (dry), friable (moist). Field pH 7.0. Gradual to -

35 - 75 Dark reddish brown (5 YR 3/4 moist); medium clay; firm (moist). Field pH 7.0. Clear to -

75 - 90 Brown (7.5 YR 4/4 moist); medium clay; firm (moist). Moderate amount of basaltic gravel. Field pH 7.0.

Site 6

AGRICULTURAL MANAGEMENT UNIT: BFs PRINCIPAL PROFILE FORM (Northcote): Ug 5.12 DATE OF DESCRIPTION: 27th February, 1980 LOCATION: Crow's Nest District, Queensland 9243 1:100 000 Sheet Number Australian Map Grid Reference 379500E 7001500N TOPOGRAPHY: Crest (3% land slope) on low, hilly terrain. PARENT MATERIAL: Tertiary basalt. PROFILE DRAINAGE: Well drained. VEGETATION: Grassy open woodland of Eucalyptus crebra (narrow leaved ironbark), some Eucalyptus ter-8tieornis (Queensland blue gum) and scattered shrubs. LAND USE: Selectively logged for grazing. MORPHOLOGY:

Depth (em) Description 0 - 10 Black (7.5 YR 2/l moist); self-mulching; medium clay; weak, medium granular; slightly hard (dry) , friable (moist). Small amount of basaltic gravel. Field pH 6.8. Gradual to -

10 - 20 Black ( 7. 5 YR 2/1 moist); medium clay; moderate, medium granular; slightly hard (dry). Abundant basaltic gravel. Field pH 7.0. I-viii

SUe_ g

AGRICULTURAL MANAGEMENT UNIT: BFd PRINCIPAL PROFILE FORM (Northcote) : Ug 5.13 DATE OF DESCRIPTION: 29th April, 1980 LOCATION: Craw's Nest District, Queensland 9243 1:100 000 Sheet Number Australian Map Grid Reference 388400E 6999800N TOPOGRAPHY: Mid to lower slope (7% land slope) on moderately undulating terrain. PARENT MATERIAL: Tertiary basalt. PROFILE DRAINAGE: Moderately well drained. VEGETATION: Eucalypt open woodland (cleared). LAND USE: Summer and winter dryland cropping. MORPHOLOGY:

Depth (em) Description 0 - 10 Black (10 YR 2/1 moist); self-mulching; medium heavy clay; strong, fine granular; slightly hard (dry). Field pH 6.8. Clear to -

10 - 35 Black (10 YR 2/1 moist); heavy clay; moderate, fine blocky; firm (moist). Field pH 6.8. Gradual to -

35 - 50 Brownish black (10 YR 2/2 moist) with a few black mottles; heavy clay; friable (moist). Field pH 7.0. Diffuse to -

50 - 90 Brownish black (10 YR 3/2 moist) with a few black mottles; heavy clay; friable (moist). Field pH 7.5. Diffuse to -

90 - 100 Dark brown ( 10 YR 3/3 moist); light-medium clay; firm (moist). Small amount of basaltic gravel. Field pH 8. 5. Clear to -

100 - 120 Brown (7.5 YR 4/4 moist); light clay; very friable (moist). Moderate amount of basaltic gravel and calcium carbonate nodules. Field pH 9.0. I-ix

BASALTIC RED SOILS LAND RESOURCE AREA r sae 4

AGRICULTURAL MANAGEMENT UNIT: Pinelands 2 PRINCIPAL PROFILE FORM (Northcote): Gn 4.11 DATE OF DESCRIPTION: 27th February, 1980 LOCATION: Crow's Nest District, Queensland 9243 1:100 000 Sheet Number Australian Map Grid Reference 397400E 6987500N TOPOGRAPHY: Upper slope position (8% land slope) on low, hilly terrain. PARENT MATERIAL: Tertiary basalt. PROFILE DRAINAGE: Well drained. VEGETATION: Softwood scrub. LAND USE: Virgin scrub. MORPHOLOGY:

Depth (em) Description

0 - 8 Dull reddish brown (2.5 YR 4/3 moist); loose surfaced; light clay; weak, very fine crumb; slightly hard (dry). Field pH 5.0. Clear to -

8 - 15 Dull reddish brown (2 .5 YR 4/3 moist); light medium clay; weak, very fine blocky; slightly hard (dry). Field pH 5.0. Diffuse to -

15 - 20 Dull reddish brown (2.5 YR 4/3 moist); medium heavy clay; weak, very fine blocky; slightly hard (dry). Field pH 4.5. Diffuse to -

20 - 30 Dull reddish brown (2.5 YR 4/4 moist); medium heavy clay. Field pH 4.5. Diffuse to -

30 - 100 Dull reddish brown (2.5 YR 4/4 moist); medium heavy clay. Trace of tuffaceous and basaltic gravel. Field pH 4.0.

S.Ue 12

AGRICULTURAL MANAGEMENT UNIT: Ravensbourne PRINCIPAL PROFILE FORM (Northcote): Gn 3.11 DATE OF DESCRIPTION: 18th September, 1980 LOCATION: Craw's Nest District, Queensland 9343 1:100 000 Sheet Number Australian Map Grid Reference 41T850E 69T2TOON TOPOGRAPHY: Crest (1% land slope) of broad convex ridge. PARENT MATERIAL: Tertiary basalt. I-x

PROFILE DRAINAGE: Very well drained (somewhat excessive). VEGETATION: Rainforest. LAND USE: Virgin rainforest. MORPHOLOGY: Depth (em) Deseription 0 - 10 Brownish black (5 YR 2/2 moist); loose-surfaced; clay loam; weak, fine crumb; loose (moist). Field pH 6.0. Gradual to -

10 - 18 Brownish black (5 YR 2/2 moist); clay loam; weak, fine crumb; very friable (moist), soft (dry). Field pH 5.8. Gradual to -

18 - 35 Dark reddish brown (2.5 YR 3/3 moist); light clay; moderate, very fine blocky; slightly hard (dry). Field pH 5.8. Diffuse to -

35 - 90 Dark reddish brown (2.5 YR 3/4 moist); light medium clay. Field pH 5.5. Diffuse to -

90 - 120 Dark reddish brown (2.5 YR 3/4 moist); light medium clay. Field pH 5.2.

SM:e 73

AGRICULTURAL MANAGEMENT UNIT: Palmtree PRINCIPAL PROFILE FORM (Northcote): Gn 3.11 DATE OF DESCRIPTION: 18th September, 1980 LOCATION: Crow's Nest District, Queensland 9343 1:100 000 Sheet Number Australian Map Grid Reference 419200E 6975700N TOPOGRAPHY: Upper convex slope on low hilly terrain (3% land slope). PARENT MATERIAL: Tertiary basalt.

PROFILE DRAINAGE: Moderately well drained; impermeable deep subsoil. VEGETATION: Layered rainforest transitional to Eucalypt open forest. LAND USE: Selective logging. MORPHOLOGY:

Depth (em) Deseription 0 - 10 Brownish black (5 YR 2/2 moist); loose-surfaced (with litter); light clay; weak, medium granular; slightly hard (dry). Field pH 6.0. Diffuse to -

10 - 35 Brownish black (5 YR 2/2 moist); light-medium clay; c weak, medium granular; slightly hard (dry). Field pH 6.0. Gradual to -

35 - 65 Dull reddish brown (2.5 YR 4/4 moist); medium-heavy clay; moderate, fine blocky; hard (dry). Field pH 5.8. Diffuse to - I-xi

MORPHOLOGY (CONT.) : Depth (em) Description 65 - 90 Reddish brown (5 YR 4/6 moist); heavy clay; hard (dry). Trace of basaltic gravel. Field pH 5.5. Diffuse to -

90 - 120 Reddish brown (5 YR 4/6 moist); heavy clay; hard (dry). Trace of basal tic gravel. Field pH 5.3.

S-Ue 15

AGRICULTURAL MANAGEMENT UNIT: Pechey PRINCIPAL PROFILE FORM (Northcote) : Gn 4.12 DATE OF DESCRIPTION: 18th September, 1980 LOCATION: Grow's Nest District, Queensland 9343 1:100 000 Sheet Number Australian Map Grid Reference 408200E 69T8700N

TOPOGRAPHY: Extensive plateau surface (3% land slope). PARENT MATERIAL: Tertiary basalt. PROFILE DRAINAGE: Very well drained (somewhat excessive). VEGETATION: Grassland, mainly Paspalum dilatatum (paspalum) and Imperata cylindrica (blady grass). LAND USE: Cleared for grazing. MORPHOLOGY: Depth (em) Description

0 - 10 Brownish black (5 YR 2/2 moist); snuffy loam; structureless; loose (dry). Field pH 6.8. Gradual to -

10 - 20 Very dark reddish brown (5 YR 2/3 moist); clay loam; structureless; loose (dry). Field pH 6.5. Clear to -

20 - 35 Dull reddish brown (2.5 YR 4/4 moist); light clay; weak, very fine blocky; soft (dry). Small amount of ironstone and basaltic gravel. Field pH 6.0. Diffuse to -

35 - 95 Reddish brown (2.5 YR 4/6 moist); light-medium clay; slightly hard (dry). Small amount of ironstone gravel. Field pH 6.0. Diffuse to

95 - 120 Bright brown (T.5 YR 5/6 moist); light-medium clay; slightly hard (dry). Small amount of ironstone

gravel. Field pH 6.8. · I-xii

SUe. 16

AGRICULTURAL MANAGEMENT UNIT: Pinelands 1 PRINCIPAL PROFILE FORM (Northcote): Gn 3.12 DATE OF DESCRIPTION: 25th September, 1980 LOCATION: Craw's Nest District, Queensland 9243 1:100 000 Sheet Number Australian Map Grid Reference 397300E 6989600N TOPOGRAPHY: Crest (2% land slope) on low hilly terrain. PARENT MATERIAL: Tertiary basalt. PROFILE DRAINAGE: Very well drained (somewhat excessive). VEGETATION: Softwood scrub (cleared), now kikuyu grassland. LAND USE: Cleared for grazing. MORPHOLOGY:

Depth (ern) Description 0 - 10 Very dark reddish brown (5 YR 2/3 moist); loose surfaced; light clay; weak, medium granular; slightly hard (dry). Field pH 6.8. Clear to -

10 - 20 Dark reddish brown (5 YR 3/4 moist); light clay; weak, fine blocky; slightly hard (dry). Trace of lateritic gravel. Field pH 7.0. Diffuse to -

20 - 40 Dark reddish brown (5 YR 3/4 moist); light clay; soft (dry). Small amount of lateritic and basaltic gravel. Field pH 7.0. Gradual to -

40 + Weathered basalt and basaltic gravel.

SUe. 17

AGRICULTURAL MANAGEMENT UNIT: Merritts PRINCIPAL PROFILE FORM (Northcote): Ug 5.13 DATE OF DESCRIPTION: 25th September, 1980 LOCATION: Craw's Nest District, Queensland 9243 1:100 000 Sheet Number Australian Map Grid Reference 404100E 6973000N TOPOGRAPHY: Saddle of dissected plateau (1% land slope). PARENT MATERIAL: Tertiary basalts. PROFILE DRAINAGE: Moderately well drained. VEGETATION: Eucalypt open woodland (cleared). LAND USE: Dryland grain cropping. I-xiii

MORPHOLOGY:

Depth (em) Description 0 - 10 Brownish black (10 YR 2/2 moist); self-mulching; medium clay; moderate, medium granular; hard (dry). Field pH 5.8. Clear to -

10 - 22 Black (10 YR 2/1 moist); medium clay; moderate, fine blocky; firm (moist). Field pH 6.0. Gradual to -

22 - 50 Dark brown (10 YR 3/4 moist); medium-heavy clay; blocky; firm (moist). Trace of lateritic gravel. Field pH 6.5. Diffuse to -

50 - 78 Brown (7.5 YR 4/3 moist); medium clay; lenticular; firm (moist). Trace of lateritic gravel. Field pH 6.8. Diffuse to -

78 - 90 Dull brown (7.5 YR 5/4 moist); medium clay; friable (moist). Trace of lateritic gravel. Field pH 6.8. Diffuse to -

90 - 105 Dull yellowish brown (10 YR 5/4 moist); medium clay; friable (moist). Field pH 6.8.

105 + Weathered basalt.

SUe 18

AGRICULTURAL MANAGEMENT UNIT: Geham PRINCIPAL PROFILE FORM (Northcote): Uf 6.12 DATE OF DESCRIPTION: 25th September, 1980 LOCATION: Grow's Nest District, Queensland 9343 1:100 000 Sheet Number Australian Map Grid Reference 403000E 6969300N TOPOGRAPHY: Mid slope position (3% land slope) on plains of moderate relief. PARENT MATERIAL: Tertiary basalt. PROFILE DRAINAGE: Poorly drained; perchedwatertable frequently occurs VEGETATION: Grassy open woodland of Eucalyptus tereticornis (Queensland blue gum). LAND USE: Extensively cleared for grazing. MORPHOLOGY:

Depth (em) Descr>iption 0 - 10 Very dark brown (7.5 YR 2/3 moist); loose-surfaced; light-medium clay; weak, fine granular; slightly hard (dry). Small amount of ironstone gravel. Field pH 6.5. Gradual to -

10 - 22 Very dark brown (7.5 YR 2/3 moist); light-medium clay; moderate, fine granular; slightly hard (dry). Small amount of ironstone and basaltic gravel. Field pH 6.5. Clear to - I-xiv

MORPHOLOGY (CO�T) :

Depth (em} Description 22 - 40 Brown (7.5 YR 4/4 moist); medium clay; moderate, very fine blocky; friable (moist). Moderate amount of ironstone and basaltic gravel. Field pH 5.5. Diffuse to -

40 - 80 Reddish brown (5 YR 4/6 moist); medium clay; friable (moist). Small amount of ironstone gravel. Field pH 5.5. Diffuse to -

80 - 90 Brown (7.5 YR 4/6 moist) with common reddish brown mottles; medium-heavy clay; firm (moist). Field pH 5.5. Diffuse to -

90 - 120 Brown (10 YR 4/6 moist) with common reddish brown mottles; medium-heavy clay; firm (moist). Field pH 5.5.

S-Ue. 79

AGRICULTURAL MANAGEMENT UNIT: Cabarlah PRINCIPAL PROFILE FORM (Northcote) : Urn 6.24 DATE OF DESCRIPTION: 25th September, 1980 (�.- . LOCATION: Grow's Nest District, Queensland 9243 1:100 000 Sheet Number Australian Map Grid Reference 398800E 6964600N TOPOGRAPHY: Crest (1% land slope) of broad flat ridge. PARE�T MATERIAL: Tertiary basalt. PROFILE DRAINAGE: Very well drained (somewhat excessive). VEGETATION: Eucalypt grassy open woodland. LAND USE: Partially cleared for grazing of native pastures. MORPHOLOGY:

Depth (em} Description 0 - 10 Very dark reddish brown (5 YR 2/3 moist); clay loam; weak, very fine crumb; soft (dry). Small amount of ironstone gravel. Field pH 6.5. Gradual to -

10 - 20 Very dark reddish brown (5 YR 2/4 moist); clay loam; weak, very fine granular; soft (dry). Moderate amount of ironstone gravel. Field pH 6.5. Gradual to -

20 - 35 Very dark reddish brown (5 YR 2/4 moist); clay loam; soft (dry). Abundant ironstone gravel. Field pH 6.8. I-xv

ALLUVIUM LA ND RESOURCE AREA

Sili 9

AGRICULTURAL MANAGEMENT UNIT: Als PRINCIPAL PROFILE FORM (Northcote): Ug 5.16 DATE OF DESCRIPTION: 29th April, 1980 LOCATION: Crew's Nest District, Queensland 9243 1:100 000 Sheet Number Australian Map Grid Reference 392500E 6991700N TOPOGRAPHY: Floodplain (1% land slope). PARENT MATERIAL: Alluvium, predominantly of basaltic origin. PROFILE DRAINAGE: Moderately well drained. VEGETATION: Eucalypt grassy open woodland (cleared). LAND USE: Dryland grain cropping. MORPHOLOGY:

Depth (am) Description

0-10 Brownish gray (10 YR 4/l moist); self-mulching; heavy clay; strong, fine blocky; very hard (dry). Field pH 6.8. Clear to -

10 - 20 Brownish gray (10 YR 4/l mois�; heavy clay; strong, medium blocky; firm (moist). Field pH 7.0. Gradual to -

20 - 30 Brownish gray (10 YR 4/1 moist); heavy clay; very firm (moist). Field pH 7.8. Diffuse to -

30- 60 Brownish gray (10 YR 4/1 moist); heavy clay; very firm (moist). Field pH 8.5. Diffuse to -

60 - 90 Brownish gray (10 YR 4/1 moist); heavy clay; very firm (moist). Trace of soft calcium carbonate segregations. Field pH 9.5. Diffuse to -

90 - 120 Grayish yellow brown (10 YR 4/2 moist); heavy clay; firm (moist). Trace of soft calcium carbonate segregations. Field pH 9.5. Diffuse to -

120 - 150 Grayish yellow brown (10 YR 4/2 moist); heavy clay; friable (moist). Trace of soft calcium carbonate segregations. Field pH 9.5 . I-xvi

�e 10

AGRICULTURAL MANAGEMENT UNIT: Alw PRINCIPAL PROFILE FORM (Northcote): Ug 5. 15 DATE OF DESCRIPTION: 29th April, 1980 LOCATION: Craw's Nest District, Queensland 9243 1:100 000 Sheet Number Australian Map Grid Reference 393400E 6994700N TOPOGRAPHY: Floodplain (2% land slope). PARENT MATERIAL: Alluvium, predominantly of basaltic and lateritic origin. PROFILE DRAINAGE: Moderately well drained. VEGETATION: Eucalypt grassy open woodland (cleared). LAND USE: Dryland grain cropping. MORPHOLOGY:

Depth (em) Description 0 - 10 Brownish black (7.5 YR 3/2 moist); surface crust light medium clay; weak, fine crumb; soft (dry). Field pH 6. 5. Abrupt to -

10 - 20 Brownish black (7 .5 YR 3/2 moist); heavy clay; moderate, fine blocky; firm (moist). Field pH 6. 8. Gradual to -

20 - 30 Brown (7. 5 YR 4/3 moist); heavy clay; moderate, fine blocky; firm (moist). Field pH 7. 0. Diffuse to -

30 - 60 Brown ( 7. 5 YR 4/4 moist); heavy clay; firm (moist). Field pH 8. 0. Diffuse to -

60 - 90 Brown (7. 5 YR 4/4 moist); heavy clay; friable (moist). Trace of calcium carbonate nodules. Field pH 8. 8. Gradual to -

90 - 150 Brown (7. 5 YR 4/4 moist); medium clay; friable (moist). Trace of calcium carbonate nodules. Field pH 9. 0.

S.{;te 11

AGRICULTURAL MANAGEMENT UNIT: Alh PRINCIPAL PROFILE FORM (Northcote): Db 1. 13

DATE OF DESCRIPTION: 29th April, 1980 LOCATION: Crow's Nest District, Queensland 9243 1:100 000 Sheet Number Australian Map Grid Reference 393500E 6994300N TOPOGRAPHY: Floodplain ( 1% land slope). PARENT MATERIAL: Alluvium, predominantly sandstone origin. PROFILE DRAINAGE: Imperfect. I-xvii

VEGETATION: Eucalypt grassy open woodland (cleared). LAND USE: Dryland grain cropping. MORPHOLOGY: Depth (em) Description

0 - 10 Brownish black ( 7.5 YR 3/2 moist) ; hardsetting; sandy clay loam; structureless, massive; hard (dry). Field pH 5.8. Gradual to -

10 - 20 Brownish black (7.5 YR 3/2 moist); sandy clay loam; structure less, massive; hard (dry). Field pH 5.8. Abrupt to -

20 - 30 Dark brown (7. 5 YR 3/3 moist); sandy clay; moderate, coarse blocky; very hard (dry). Field pH 6.0. Diffuse to -

30 - 60 Dark brown (7.5 YR 3/3 moist); medium-heavy clay; moderate, coarse blocky; very hard (dry). Field pH 7.8. 3. KeY to the AMU s of the Ba sa lt Ea st LRA

Brownish black clay loam to light clay over brown to yellowish brown light to medium clay with gravels by 45 em, Occurs on ridges and upper slopes in

softwood scrub areas •..... o • o • o o. 0 ••••••••••••••o ••••••••••••••••••••••••••••••••••••••••BSs

Soils < 45 em deep Brownish black clay loam to medium clay, uniform colour throughout; gravels and small stone throughout but increasing with depth. Occurs on ridges and slopes in

forest areas ...•...... o ••••••••••o ••••o ••••••••0 •••••••o ••••••• o •••• ••••o • • • • • • • • • • • BFs

Narrow valleys with short, Brownish black, weakly cracking medium to heavy steep pediments; softwood clay, fine granular surface grading to blocky scrub with some eucalypts. dark reddish-brown heavy clay; carbonate by 50 em; non-gilgaied; occurs on lower slopes and valley floors...... BSd

Brownish black, cracking heavy clay, strong granular surface over yellowish brown medium clay with carbonate increasing below 45 em;

Basalt East generally > 1m deep on mid to lower slopes. BFd LRA Brownish black light clay, weak fine crumb to Broad valleys with long, structureless surface over weak blocky, dark low gradient pediments; reddish brown subsoil. No carbonate present; Soils > 45 em deep eucalypt open forest and only weakly cracking in virgin condition but grassy open woodland. cracks more strongly with cultivation and loss

of Al horizon •...... 0 •••••••••••••••o...... BFwd I-xix

{ 4. KeY to AMUs of the :Sasalti� Red Soils LRA Crack1ng clay -- Self mulch1ng med1um to heavy clay, moderate granular surface over brown !llEldlum to heavy clay ;nth rounded basalt and lat1lity CoU,w1al soli der1ved gurfac

Non-Crack1ng Weak granular, occas1onally hardseteing surface, clay ironstone and laterite gtavels in dark A horizon overlying reddish to yellowish brown light to medium clay gra

Structureless Reddish brown to bright brown light snuffy surface-- to me.dium clay fine blocky subsoil with increasing amounts of ironstone Loam to clay and laterite gravels, some Mn nodules; loam surface plat"-aux and dissect"d plateaux remnants. Associated with eucalypt open forest...... PECHEY

Fine crumb to < 35 em de"p to -- Reddish brown loam to clay loam

surface latei:ite gravels clay Increas1ng amounts of or rnass1ve 1ronstone and later1te gravel later1te overly1ng hard to mass1ve latente, occurs on r1dges and plateaux remnants Assoc1ated with eucalypt open forest...... CABARLAH

B 35 em deep -- Fme blocky red to reddish brown Red Soils light clay subsoil with increasing m amounts of laterite gravels; > 150 d"-ep 8l>d may be many metres deep; slightly acid throughout; fr"ely drai.ning; occurs on plateaux and 3teep slopes. Associated with . • . . . • rainforest...... RAVENSBOURNE

Developed. an Gunular to fine blot.ky surfat.e weath"red --- ovar reddish brown. blocky light basalt to mfodium clay with basalt gravel and floaters; pH neutral throughout; some lateritic gravels; occurs on benches and plateaux remnants generally below Pinelands 2 AMU. Asso<::iated with softwood scrub. PINELAND$ l

Structureless surface with no dark organic A horizon over fine blocky light to medium clay of dull reddish brown to yellowish red colour; pH 3.5 � 5.0 throughout; occurs on plato;aux and steep slopes associated with Pinelands 1 AMU. Associated Dark r<:lddish <->ith softwood scrub ...... •... PINELANDS 2 brown to reddisll brown Light clay Developed on Moderate granular surface over brown surfac<:l soil surface laterite or to rfoddish bro<->n fine blocky medium tuffaceous clay ov"r rrroeel"d reddish ra yellowish material brown. medium clay; JOOderately impermeable by 100 em; pH 6.5 throughout; occurs on slopes and low ridg"'S. Associated with eucalypt forest/softwood scrub areas ... II-i

APPE NDIX II

Soi l AnalYtica l Da ta for RePresentat ive Profi les

of the Basa lt East, Basal tic Red

Soi ls and Al luvium Land Resource Area·s

S.E. Macnlsh II-ii