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Land resources series Natural resources research

1991

Land capability study for horticulture in the Swan Valley

J M. Campbell-Clause

Geoff Allan Moore

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Part of the Natural Resources Management and Policy Commons, Soil Science Commons, and the Viticulture and Oenology Commons

Recommended Citation Campbell-Clause, J M, and Moore, G A. (1991), Land capability study for horticulture in the Swan Valley. Department of Primary Industries and Regional Development, Western Australia, Perth. Report 6.

This report is brought to you for free and open access by the Natural resources research at Research Library. It has been accepted for inclusion in Land resources series by an authorized administrator of Research Library. For more information, please contact [email protected]. ISSN 1033-1670 AGDEX 526

L AN D RE S 0 U R C E S S E R I E S No.6

Land capability study for HORTICULTURE IN

a By J. Campbell Clause and G. A. Moore DEPARTMENT OF AGR ICULTURE - WES TER N AUSTRALIA Land capability study for HORTICULTURE IN THE SWAN VALLEY

By: 1. Campbell Clause and G. A. Moore

Editors : L.J. Snell and D.A.W. Johnston Design by: L.T. Webb

LA ND RESOURCES SERIES NO.6 April 1991 DEPARTM ENT OF AG RICULTURE Baron-Hay Court South Perth 615 1 WESTERN AUSTRALIA ISSN 1033- 1670 AGDEX 526

0663·1

, . The authors: J. Campbell Clause, Research Of­ ficer, Viticulture Branch, Division of Horticulture; and G.A. Moore, Research Officer, Land Evaluation Group, Division of Resource Ma n­ agement, Department of Agri cul­ hue, Western Australia.

National Library of Australia Cataloguing-in-Publication entry

Campbell Clause, J. (James), 1964- Land capability study for horticul­ ture in the Swan Valley.

Bibliography. ISBN 0 7309 3926 X. 1. Land capability for agricul­ ture - Western Australia­ Swan River Valley. 2. Horti­ culture-Western Australia­ Swan River Valley. 3. Land use-Western Australia­ Swan River Valley - Plan­ ning. I. Moore, G.A. (Geoff Allan), 1960- . II. Western Australia. Department of Agri­ culture. Ill. Title. (Series: Land Resources Series No.6). 631.479412 © Chief Executive Officer of the Department of Agriculture, Western Australia 1991.

LAND RESOURCES SERIES No.6 2 The Swan Valley is an important culture's Geographic Information agricultural, recreational, tourist System (digital data base) to enable Summary and heritage area in which there in terpretative analysis and repro­ are a number of competing land duction of special purpose maps. uses because of its location close to Perth. The traditional agricultural A corridor of prime horticultural use, mainly centred around the land for table grape production has viticulture industry, has to com­ been identified adjacent to the pete with tourist development, Swan River and corresponds to the urban encroachment, hobby farms Swan, Belhus, Houghton, Pyrton, and clay extraction. The major Herne and Cruse soil series. This objective of this report was to corridor would be suitable for a identify any areas of prime horti­ special horticultural zone within cultural land which should be re­ the Swan Valley, with the bounda­ tained for that purpose. ries corresponding to the existing Swan Valley Rural Zone. Tight A land capability study was control over alternative land uses done using the existing soil series would be needed to protect the map of the Swan Valley (Pym prime agricultural land and ensure 1955), which covers most of the the long term prosperity of the Swan Valley Policy Area. The map table grape industry. The compet­ units were assessed for 11 land ing land uses include subdivision, qualities (e.g. site drainage, rooting tourism and clay extraction. conditions) which were then re­ lated to the land use requirements Included with the report are to derive the land capability rat­ maps showing the soil types ings. The ratings for six horticul­ (1:25,000) (Pym 1955) and the land tural crops: table grapes, wine capability for table grapes grapes, dried vine fruit, stone fruit, (1:50,000). Land capability maps for citrus and market gardening were the other land uses assessed are determined. Map production was available from the Department of done by the Department of Agri- Agriculture on request.

3 LAND RESOURCES SERIES No.6 00663·2 Page

Contents Summary 3 Introduction 7 Swan Valley Policy 10 Study objectives 10 The Study area 11 Methodology of land capability assessment 12 Soil maps used 12 Land capability classification 12 Climate 15 Groundwater 17 Groundwater resources 17 Groundwater availability 17 Allocation 19 Land use requirements 20 Viticulture 20 Table grapes 21 Wine grapes 21 Dried vine fruit 22 Citrus 23 Stone fruit 23 Market gardening 24 Soils and land use limitations 25 Discussion 29 Acknowledgements 33 References and bibliography (includes references in Appendices 3, 5 and 6) 34

Appendices 1. Land capability classes 37 2. Land qualities assessed for each map unit 39 3. Land quality descriptions and values 42 4. Land capability rating tables for each land use type 51 5. Maps available on the GIS 57 6. Groundwater resources of the Swan Valley 58 7. Maps 59

LAND RESOURCES SERIES No.6 4 Page

List of figures 1. Land use map (1953) 8 2. Land use map (1988) 9 3. Location of tlie study area 11 4. Location of soil maps 13 5. Flow diagram showing land capability assessment procedure 14 6. Wind roses for the Upper Swan Research Station 16 7. The Swan Groundwater Area and the ten sub-areas 18 8. Location of the Swan Valley Rural Zone in relation to prime horticultural land for table grape production 31

List of tables 1. Land capability classes 14 2. Land qualities assessed for each map unit 14 3. Climatic data for the Upper Swan Research Station 16 4. Groundwater availability and licensed allocations for the Swan Groundwater Area 19 5. Crop factors for various stone fruit over the growing season 24

5 LAND RESOURCES SERIES No.6

The Swan Valley is one of the The Swan Valley has been an most important agricultural, rec­ important viticultural area with Introduction reational and tourist assets close to production peaking in the late Perth. The valley contains alluvial 19405 when about 4000 ha were soils which are highly productive under vines. The main industry at for horticulture. The climate and that time was dried fruit with small soils of the valley permit the pro­ but significant wine making and duction of premium quality table table grape industries. The area grapes and quality wines, particu­ planted to vines has contracted to larly the fortified styles. The valley about 600 ha (1988), with large also contains reserves of plastic areas of Mangin series and mar­ clay used for brick making. Large ginal Herne series soils being taken brick works and tile works are out of production. The reason for located at Middle Swan and Caver­ this decline can be attributed to sham. The valley' 5 scenic and his­ changing economic conditions, toric attractions, coupled with its management technique problems, proximity to Perth, nlake it a waterlogging and the move away prominent tourist attraction with from dried fruit production. Land outstanding potential for further use in 1953 is compared with land development. These same attrac­ use in 1988 (Figure 1 and Figure 2 tions are the reasons why the Swan respectively). Table grape produc­ Valley is under pressure from a tion is now the most important number of conflicting land uses, industry in the Swan Valley, sup­ Tlte Swan Valley is a fllra! area Witll vineyards and pastures dominating the landsca pe. The area including urban expansion, hobby plying both the local and export is Ilnder pressu re fro m conflicting lan d uses. farms and development. markets. High returns per unit area are possible on suita ble soils using sound managen1ent techniques. Also significant is the winema king industry, wi th about 80% of the State's wine being made in the valley. Horticulture in the Swan Valley is under pressure from a number of other land uses. Urban encroach­ ment and subdivision for semi­ rural living, with the subsequent increase in land values within the valley, probably pose the greatest threat, although clay excavation, tourism and other uses (e.g. schools) are also eroding the horti­ cultural base. The valley starts only 15 km from the centre of Perth and is adjacent to the burgeoning urban sprawl of the greater Perth Metro­ politan Area. Other factors which may increase demand for residen­ tial and hobby farming land in the valley include the significant price increase for residential land near Perth in the late 1980s and the development pressures created by the adjoining semi-rural subdivi­ sion at Brigadoon and the 'Vines Country Club' with accompanying residential development.

7 LAND RESOURCES SERIES No.6 - LEGEND-

L V'NES ______. ______~ 2 IDLE LAND [formerly vinesJ ______..• 3. IMPROVED PASTURE [formerly vm~s] ______~ ______4. 21Jl"3 [formHly vinesl ______

5. ORCHARDS [mamiy ';',"']n _n 1:·:·:·:1 6. IMPROVED PASTURE ______[7z:J 7. UNCLEARED, ROUGH GRAZING.B --""."M 8. GRAVEL RESERVES ______D 9. CLAY PITS ______C

SCALE

1""0"'1""'i __iL] ==:r=::i2 Ian

Complied 0/ L Wf!ym 1953

Figure 1. Existing land use map of the Swan Valley vineyard area (1953) (From Pym 1955).

LAND RESOURCES SERIES No.6 8 \ I I

I I --l j' ~

legend Vineyards

Swan Groundwater Afl'J OrchMds

Swan Valley Policy Area

main road Quarry

r,lilw,l\- Industry, brickyJrds ~~ ril-er,Cfl'l'K

Figure 2. Land use map (March 1988). (base map courtesy of Department of Planning and Urban Development)

9 LAND RESOURCES SERIES No.6 Swan Valley Policy Swan Valley's unique resources. As with adequate information with The Government of Western a means to achieving this, two which to assess the impact of devel­ Australia's Swan Valley Policy zones have been identified and opment proposals on the valley (Anon. 1985) identifies a need to implemented by the Shire of Swan: and to achieve the objective of the revitalize and conserve the Swan (a) the Swan Valley Rural Zone; zoning. Valley. The Government makes a and The Swan Valley Policy lists spe­ commitment in its policy to re­ (b) a rural living zone (to act as a cific objectives and indicates Gov­ taining the Swan Valley as an buffer to the Rural Zone). ernment action, including the man~ agricultural, recreational and tour­ agernent of groundwater resources ist asset. The Swan Valley Policy The objective of zoning is to in the Swan Valley. This involved a 'Specific Objective 9', states that 'promote the area primarily as a review of the current policy of the future planning for the valley's horticultural, recreational, tourism Water Authority of Western Aus­ natural and built environment and landscape resource, with areas tralia (in this publication referred should: containing high quality horticul­ to as the Water Authority) in rela­ tural soils and scarce plastic clays tion to water supply. In, 'Ground 1. ensure that important re­ receiving special protection'. (Shire sources such as horticultural water allocation policy and man­ of Swan Town Planning Scheme agement study', D.A. Hooper soils are not jeopardized by No.9 Section 8.2.2). incompatible development or (1986, unpublished) recommended subdivision; The Shire of Swan's existing that the Department of Agriculture Swan Valley Rural Zone (Figure 8) prepare a detailed land use map 2. lninimize developments and occupies the central, highly pro­ and land capability description for activities which conflict with ductive part of the Swan Valley viticulture. the quality of the valley as a Policy Area. It is supported by A report for the Sta te Planning horticultural, tourist and rec­ statements of planning policy such reational area (Anon. 1985). Commission by Nesic (1987), 'Pro­ as 'the Council shall not approve of posed Swan Valley land use and The Government's primary ob­ any development which would subdivision', included a prelimi­ jecti ve for conserva tion and plan­ jeopardize the high quality nary land capability assessment for ning is to conserve and enhance the horticultural soils'. However, high viticulture. The fact that arbitrary quality horticultural soils and land planning decisions were included considered suitable for horticulture in the land capability assessment, are not defined nor described or and it lacked information on areas located on a map. These planning considered marginally suitable, or policy statements are thus of lim­ The SWmI Valley is renowned for its high quality not suitable, are shortcomings. Our table grapes . ited value in providing the Council report aims to overcome these defi­ ciencies.

Study Objectives The objectives were; • To provide a detailed land capa­ bility assessment for horticul­ ture, in particular for viticulture, in the Swan Valley. • To identify any prime hor­ ticultural land which should be retained for horticulture. • To provide an updated land use map for the Swan Valley. To fulfil the Swan Valley Policy objectives, it was necessary to make a clear delineation of the suitable horticultural soils in the Swan Val­ ley. Even though there is extensive local knowledge on the per­ formance of vines on various soil types in the Swan Valley, there was a need to formalize this knowledge. This report combines the available knowledge of the physical re­ sources of the valley (climate, soils and groundwater) and assesses the horticultural capability.

LAND RESOURCES SERIES No.6 10 The study area in the south, to the Swan River, The Swan Valley is a scenic, north-east of Guildford. semi-rural area commencing 15 km The Swan Valley is a licensed from the Perth city centre. The groundwater area under the con­ study area discussed in this report trol of the Water Authority. The includes two overlapping areas: Swan Groundwater Area includes the Swan Valley Policy Area and most of the policy area, but is the Swan Groundwater Area (Fig­ larger. It extends north from the ure 3). Great Eastern Highway to The borders of the Swan Valley Warbrook Road in Bullsbrook. In Policy Area are West Swan Road in the east to the foothills of the the west and the foothills of the Darling Scarp and, to the west, it Darling Range in the east. To the extends through to the low sandhill north it extends to Ellen Brook and, country west of West Swan Road.

study area

Gnan ara Road

Gt. Eastern Hwy

" '" .....N O,:-__5~ __ ..;.1 OK m

Figu re 3. Location of the study area

11 LAND RESOURCES SERIES No.6 This study involved the assess­ and Wells 1990) and from the ment of existing soil maps for a CSIRO archives. Methodology of land range of viticultural and other hor­ An updated map of land use in capability assessment ticultural crops. the Swan Valley was prepared through the interpretation of aerial Soil maps used photographs taken in April 1987, together with field verification. The Some six published and unpub­ land use requirements and factor lished soil maps cover all or part of rating tables for the viticultural the study area. Two of these maps land uses were developed in con­ (Northcote et af. 1967, Churchward sultation with I. Cameron (Depart­ and McArthur 1980) were, at a ment of Agriculture). The factor broad scale, unsuitable for a de­ rating tables for citrus, stone fruit tailed land capability assessment. and market gardening were The spatial distribution of the most adapted from a study of the poten­ detailed soil maps in the Swan tial for horticulture on the Swan Valley is shown in Figure 4. Most of Coastal Plain (Moore 1990). For the Swan Valley Policy Area is flood hazard assessment, see the covered by a detailed soil series Water Authority. map (Pym 1955) which involved a survey on a 200 m grid together with aerial photographic interpre­ tation. The main deficiency of the Land capability classification map for land capability assessment Land capability is the ability of is the variable drainage status of the land to sustain a specific use the Herne and Cruse Soil Series as without undesirable on-site or off­ mapped. We did not have the site land degradation. The proce­ resources to re-map these two umts dure used for deriving capability which cover a significant area. ratings for the six types of land use The soil series map (Pym 1955) considered is described. and the environmental geology Capability classes maps were used for the land capa­ bility assessment. The land capabil­ A five class system is used by the ity interpretive maps are only Department of Agriculture to de­ available for the area covered by scribe land capability. Land capa­ the soil series map (Pym 1955). (See bility classes indicate the degree of Appendix 5 for the list of maps severity of physical limitations to a available). In our work, map units particular land use, together with which have similar values for the levels of management needed to land qualities assessed, and essen­ contain any subsequent land deg­ tially similar soil profiles, have radation (Table I). It ranges from been grouped together. For exam­ Class I, which signifies a very high ple, Lotons sand, Lotons gravelly capability with few limitations for sand and Lotons gravelly sandy the proposed land use, to Class V loam have been grouped together which is regarded as prohibitive under Lotons series. for the specified use. The quality, or qualities which are the limiting The map units were evaluated factors for a land use are shown as for 11 land qualities (Table 2). The letter notations (Table 2). No letter evaluation consisted of information notation is shown for units rated as from the relevant published re­ Class I, because there are no signifi­ ports, local experience and field cant limiting factors. investigations. The field investiga­ tions involved detailed soil profile Derivation of the classification: descriptions using the 'Australian soil and land survey field handbook' The land capability methodology (McDonald et al. 1984) at 50 repre­ was broadly based upon the land sentative sites (determined from evaluation guidelines developed the map unit description), together by the Food and Agriculture Or­ with the physical features of the ganization of the United Nations landscape including the topogra­ (FAO 1979, 1983). The procedure is phy and rock outcrop. In addition, outlined in Figure 5. reference was made to site descrip­ tion sheets from the Darling Range rural land capability study (King

LAND RESOURCES SERIES No. 6 12 legend 5(lurce of 5(lil mapping

Sw~n Valley Vineyard (Pym-1953l

Swan Groundwater Ared D.1rling Range Rural (Killg ffnd Wdl>--J990)

Swan Valiey Policy Area Environmental Geology Series (GtologiclIl 51tn'ty 0{ WA-J98J)

main road Midland Junction (Smith Qnd l\'u/5IIn-J946) railwav ~ river, en"'\:.

Figure 4. Soil maps available of the Swan Valley

13 LAND RESOURCES SERlES No. 6 Steps involved: • Select the relevant land qualities, Table 2. Land qualities assessed for each • Define the land use(s) considering the land use(s) to be map unit assessed. A land capability classification Land quality Symbol inherently relies on specification Land qualities are those attrib­ of the land use type. For exam­ utes of land which influence its ple, land may be too water­ capability for a specified use. The Plant requirements: logged for vines, although it is land qualities selected are listed Site drainage ideal for grazing. In this study, Moisture holding capacity m in Table 2. Descriptions of each Nutrient retention n the land use types considered land quality, plus value descrip­ Rooting conditions relevant to horticulture in the tions, are in Appendix 3. Salinity hazard y Swan Valley were; table grapes, Flood hazard f wine grapes, dried vine fruit, • Formulate the 'land use require­ Management requirements: stone fruit, citrus and market ments' in terms of land quality Soil workability k gardening. values (i.e. factor rating tables). Potential for mechanization q Conservation requirements: Table 1. Land capability classes Wind erosion hazard w Water erosion hazard e Class I: Areas with a very high capability for the proposed activity or use. Very few Soil structural decline hazard 5 physical limitations to the specified use are present, or else they are eaSily overcome. Risk of land degradation under the proposed use is negligible. Class 11: Areas with a high capability for the proposed activity or use. Some physical limitations to the use do occur, affecting either its productive use, or the hazard The factor rating tables for each of land degradation. These limitations can be overcome through careful planning. land use are in Appendix 4. Class III: Areas with a fair capability for the proposed activity or use. Moderate physical • Assess each map unit for each limitations to the land do occur which will significantly affect productive use land quality. or result in moderate risk of land degradation unless careful planning and conservation measures are applied. See Appendix 2 for a summary of the assessed land quality values Class IV: Areas with a low capability for the proposed activity or use. There is a high for each map unit. degree of physical limitation which is not easily overcome without extensive application of conservation measures. t Matching of requirements using Class V: Areas with a very poor capability for the proposed activity or use. The severity factor rating tables. of its physical limitation prohibits its use because of the high risk of degradation or high development costs. t Land capability classification as determined by the 'most limiting factor' method. The capability ratings for each land capability land resource map unit are summarized in assessment survey Appendix 1, with the limiting land qualities shown as letter I notations. For example, an area define la nd use (1) designated as IIImn for citrus has only a fair capability for produc­ ing citrus fruit, because of the I moisture holding capacity and .. select relevant nutrient availability of the soils. land qualities (2)

landI use assess map reqUirements (3) units (4)

matching via factor rating table (5)

land capability classification

Figure 5. Flow diagram showing land capability assessment procedure

LAND RESOURCES SERIES No.6 14 The Swan Valley (Latitude 31 ' Mean daily minimum tempera­ 53'S Longitude 116'00') has an tures vary between 6.TC for Au­ Climate average altitude of 10-15 m. The gust to 16.2'C for February with the climate is typically Mediterranean lowest recorded, -O.9'C in June with a hot dry summer and a mild, 1968. Most deciduous plants have wet winter. some requirements for exposure to Olmo (1956) believed that the low temperatures during the dor­ climate of the Swan Valley was mant phase (chilling hours). The especially well suited to the pro­ lack of chilling hours restricts the duction of currants, table grapes potential for deciduous plants that and sweet dessert wines. It is also have a moderate to high chilling well suited to other horticultural requirement. crops with a low chilling require­ There are about six days per year ment. when the temperature falls below The Swan Valley is a warm 2.2'C On average, there are no viticultural area, with a total of days where the temperature drops 2388("C) day degrees between Oc­ below O'C However, frosts do tober and April. High growing occaSionally occur in june, july, season temperatures characteristic August and September. Spring of the Swan Valley are important in frosts can be particularly damaging the production of dessert wines, to vines. sweet table grapes and for drying. Mean daily terrestrial tempera­ They are important for two rea­ ture varies between 4.3 and 13.9'C, sons; to produce adequate foliage the lowest recorded was -4.3 °C in to ripen the crop and to achieve a july, 1969. On average, there are high sugar content in the berries. three days per year when terrestrial temperature falls below -0.9 "C Temperature data for the Upper Swan Research Station, which is The annual average rainfall is slightly north of the main grape about 736 mm, mostly falling dur­ growing area, is shown in Table 3. ing \>\Iinter (Table 3) . Rain from Mean daily maximum tempera­ April to September is important fo r tures vary from 18.2"C for july to replenishing subsoil moisture stor­ 33.6 'C for january and February. age. On average, there are 133 mm The highest temperature recorded of rain in spring (September­ in summer was 46.2°C in January November) and only 31 mm 1980. Heat wave conditions when through the ripening period Current Department of Agriwlture researell ill the Swall Valley ineludes assessing the effect of temperatures are high for several (December-February). This pattern willd 011 table grape productiol1, alld how wind days, can cause sunburn to vine, is advantageous as frequent falls of pro/retiol/affects yield and qllality parameters. melon, vegetable and fruit crops. rain during the ripening period, accompanied by high humidity, can result in fungal diseases and splitting of the grape berries. Hail is not frequent, however, it has occurred in March, June, July, August, September, October and November. Hail can damage foli­ age and fruit if it comes at a critical stage in the growth or ripening phase.

Evaporation in the Swan Valley is greater than the average annual rainfall. Evaporation over the growing season (October-March) is 1460 mm. For summer growing crops, such as vines, this moisture deficit must be made up from soil moisture reserves or irrigation.

1S LAND RESOURCES SERIES No.6 Table 3. Climatic data for the Upper Swan Research Station

Month jan, Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec.

Mean daily maximum CO 33.6 33.6 31.1 26.4 22.2 18.9 18.2 18.7 20.3 23.7 27.1 31.2 Mean daily minimum CO 15.2 16.2 14.5 11.5 9A 8.5 7.7 6.7 7.8 8.7 10.9 13.7 Days 2.2" or lo\ver 1 1 2 1 1 Days O' lower 0 0 0 0 0 0 0 0 0 0 0 0 Mean daily terrestrial ('0 12.6 13.9 11.9 9.6 6.8 5.8 S.l 4.3 5.0 6.3 8.3 11.7 Rainfall mm (31 years) 8 12 14 39 99 15-1 160 106 68 42 23 11 Relative humidity % 48 49 52 65 72 79 80 77 71 59 55 47 Evaporation (mm) 213.7 196.4 176.8 110.6 75.9 68.8 45.9 53.0 78.5 120.7 181.8 253.9

Januarv February The Swan Valley is renowned for 9a.m: 9 a,lll. its windiness. In spring, the strong­ est winds are generally from the west and south-west and can dam­ NW N :-X'E \ , w: age vine and fruit tree shoots, "'~ ~ resulting in a loss of production. Storm winds in spring can cause extensive shoot damage to vines, especially to susceptible varieties in exposed situations. In sun1mer, the prevailing winds are predomi­ SW SE SW nantly from the east during the SE night and morning and from the S 5 south-west in the afternoon (Figure 6). Strong, hot easterlies can dam­ age fruit, foliage and lower yield. The sea breeze is generally benefi­ January February cial through the lowering of tem­ 3p.m. 3p.m. peratures, although, when strong, N can damage crops, The areas most susceptible to the winds from the NW/ ~E NE east are the localities east of the / Swan River i.e. (Middle Swan, Herne Hill, Millendon and Upper Swan). Caversham and the area .- ~- E south of Henley Brook appear to be lo cr" N , more favourably situated to with­ I " \ stand winds from the east to south­ SE ' 0" east. SE

s

JX'r cent frequency i?J - - __-I• km/h CALM ~ ~ ~ ~:? t - = N g A

Figure 6. Willd roses for the Upper $wall Research Statioll

LAND RESOURCES SERIES No.6 16 Groundwater resources Groundwater availability Groundwater The Rights ill Water mId Irrigatioll The estimated availability and Act of 1914 provides for areas to be license allocations within each sub­ proclaimed and within these areas area are summarized in Table 4. construction of wells and use of This is an updated version of Table groundwater must be licensed. The 1 derived from D.A. Hooper (1986, Swan Groundwater Area was pro­ unpublished) and it takes into ac­ claimed in September 1975, follow­ count the results of the pasture ing concern over the use of wa ter survey (Anon 1986), plus subse­ from the Leederville aquifer in quent licenses which have been areas where the aquifer is non­ issued. The availability figures as artesian and not subject to controls. given by D.A. Hooper (] 986, un­ During 1981, it became apparent published) originate in the reports that demand needed to be con­ by Allen (1980) a nd Steen (1984) trolled. The abstraction from the and are equivalent to 100% upper Leederville aquifer (private throughflow. 3.5 x 106m3/ a, public requirements The superficial formations can be 1.3 xl06m3/a; total 4.8 x 106m3/ a) considered as the eastern and west­ approaches the flow rate which is ern superficial depending upon believed to be 5 x 106m3 / a. Thus where they are in relation to the the groundwater is fully commit­ S,'\'an Ri ver. There is considerable ted to existi ng users (R.E. Banyard water available in the western su­ 1985, unpublished). This led to the perficial formation in the North, formation of the 'Swan Groundwa­ Belhus and Henley Brook sub­ ter Advisory Committee' to Inan­ areas. This water is mainly in areas age the groundwater resources of of deep sandy soils on the western the Swan Valley. Figure 7 shows side of the sub-area. There are more the boundary of the Swan Ground­ limited supplies unallocated in water Area and the ten sub-areas. Caversham, South and West Swan. The sub-areas include, from north It appears as if the groundwater in to south; North, Upper Swan, the eastern superficial is fully com­ Belhus, Millendon, Henley Brook, mitted (see Table 4). The Water Herne Hill, West Swan, Middle Authority has reservations about Swan, Caversham and South. The the validity of the water availabil­ fresh groundwater resources of the ity data for this area as given by Swan Valley are within three main D.A. Hooper (1986, unpublished). aquifer systems, the unconfined It is difficult to reliably determine superficial formations and the con­ the available water resources of the fined Osborne and Leederville for­ eastern superficial, because two Tlte Swan River, has allowed for the development mations. The aquifers are described adjacent bores (within 150 m) can of river crrlises takhlg tOl/rists 011 wille tasfillg in Appendix 6. excursiolls. have substantially different ab­ straction rates O. Seymour, per­ sonal communication}. The alloca­ tion to availability percentage from the superficial formation for the Millendon, Herne Hill and Middle Swan sub-areas are probably mis­ leading. In the future, there could be a change in policy for water allocations from the eastern super­ ficial adjacent to the Swan River. If water is available then users may be able to extract it (R.E. Banyard, personal communication). The Leederville formation is the main aquifer used for irrigating horticultural crops in the Swan Valley. In all the sub-areas, apart from Herne Hill, Millendon and South there are limited quantities presently unallocated. The Osborne formation has a fairl y Jow overall allocation to availability ratio. Most of the unallocated

17 LAND RESOURCES SERIES No.6 ,...,. r L ___ i I i --;;\--- --~ ! j L,~ ~ BELHUS '"'---'. . . o \ ~ I .'- 1-

. -. , r

.m

Swan \'~II ..y Policy Are"

Figllre 7. The Swan Grollndwater Area alld the tell sub-areas

LAND RESOURCES SER IES No. 6 18 groundwater is in the North, To ensure the equitable distribu­ lives. In the future the demand for Belhus and Henley Brook sub-areas tion of groundwater, the Swan the limited water supplies will be underlying sandy soils. Groundwater Advisory Committee greater. R.E. Banyard (1985, unpub­ The available data show there is (with representatives from the lished) states: Water Authority, Grape Growers no unallocated water in any of the 'As development occurs the condi­ Association, Swan Valley and Re­ aquifers for Herne Hill and Millen­ tions and restrictions on water use gional Winemakers Association, don (Table 4). D.A. Hooper (J986, will become more stringent and Shire of Swan and the Department unpublished) states that 58% and users will be required to be more of Agriculture) advises the Water 48% of the total allocation is for efficient in water use. Re-allocation horticulture (viticulture and mar­ A~thority on groundwater matters of existing use to more beneficial ket gardening) in Herne Hill and and license applications. The pri­ users must be considered'. Millendon respectively. In these mary objective of the committee is: As a result of the study by D.A. two sub-areas, where availability is 'to harvest water at a sustainable Hooper (1986, unpublished), the critical, then allocation for pasture level to conserve and protect the introduction of an Allocation Prior­ and fodder could be reduced. Sub­ long term security of the g round­ ity System was recon1mended . stantial savings in water efficiency water resources of th e region and could also be achieved by using ensure that the use of the resource This should be based on the low volume irrigation systems benefits as many people as possi­ following criteria: scheduled efficiently. ble'. (a) Priority areas. The Swan Groundwater Advi­ (b) Priority in efficient use. sory Committee adopted the fol­ Allocation lowing detailed objectives to com­ (c) Priority uses. The Water Authority's current plement this primary objective. (d) Priority for quality require­ allocation policy for the Swan • To ensure that, where possible, a ments. Groundwater Area is as described reasonable quantity of water is (e) Priority for low volume irriga­ by Banyard (J 985, unpublished). available to existing enterprises tion. The groundwater management ob­ dependent upon a continued (f) Priority of allocation for spe­ jectives are: supply of good quality ground­ cific uses. • The water resource must not be water. significantly and permanently • To promote the allocation of the The system being used in the damaged from over use or pollu­ available groundwater resource Swan Groundwater Area follows tion. on a basis which provides the these criteria. In the different sub­ areas availability and allocation is • The present users should be pro­ most beneficial use to the com­ munity. determined for each aquifer. Li­ tected wherever reasonable. cences are granted specifying the • To encourage efficiency in water amount of water that can be used • The groundwater flow systems use through improvements to and the depth from which water must be measured and moni­ methods of agriculture and irri­ ca n be drawn. Priority is given to tored. gation and encourage the devel­ horticulture and more specifically opment of low water use crops, • Water use must be monitored. to vi ticulture, with up to 5000 KL/ such as vines, consistent with the ha being allocated for table grapes • The user of most benefit to the regional planning and land use and 3000 KUha for wine grapes community should be given objectives fo r the area. highest priority. per year. Where wa ter is sca rce, the Relevant strategies have been system works on a first in first • Water must be used efficiently. implemented to meet these objec- served basis.

Tabl e 4. Groundwater avai lab ility and licensed allocations for the Swan Groundwater Area

Sub-area Superficial Leederville Osborne Avail. AIIoe. %(1) Avail. Alloc % Avail. AIIoe. % 1()()()'s cubic metres per year

Belhus 6,000 884 15 700 380 54 450 12 3 Caversham 800 192 24 500 336 67 225 285 127 Henley Brook 1750 338 19 350 130 37 315 15 5 Herne Hill 200 379 19(J 400 431 108 90 79 88 Millendon 250 460 184 350 678 194 135 98 73 Middle Swan 75 503 670 350 244 70 68 0 0 North 7,000 226 3 900 118 13 621 103 17 South 270 60 22 450 1,284 285 45 3 7 Upper Swan 223 950 758 80 207 21 10 West S\van 600 438 73 550 364 66 270 182 67 Total 16,945 3,703 5,500 4,723 2,426 798

(1) Percetage of available groundwater allocated as at March 24, 1988.

19 LAND RESOURCES SERIES No.6 Viticulture winds can have detrimental effects through: Land use requirements The general requirements for vines are described, followed by • Damage to young vines; strong the specific requirements for table winds can physically damage grapes, wi ne grapes and dried vine young vines in their first and fruit. second seasons and make train­ ing of the vine difficult. It can also ca use losses and dalnage Climate through sand blasting, desicca­ Grapevines will grow under a tion, shoot rubbing and break­ range of climatic conditions, al­ ages. though they prefer a long, warm • lodging of foliage exposing fruit dry spell as they mature. low and/ or crowding of foliage, re­ temperatures have a minimal effect ducing light penetration. other than to slow growth. Grape­ vines are frost tolerant during the • Increasing the water loss from dormant phase, although highly the root zone, through evapora­ susceptible to spring frosts. High tion. temperatures (> 35 'C) can cause • Persistent strong winds can dam­ sunburn of the fruit if the crop has age foliage, reducing the effec­ not been previously conditioned by tive leaf area for photosynthesis. warm weather. Very hot conditions • Both young vines a nd older (> 40 'C) can cause severe sunburn, vines make better growth if pro­ although damage can be controlled tected from strong winds, be­ with management techniques (Le. cause at low wind speeds sto­ adequate foliage, proper trellising, matal conductance is higher. irrigation management). Rain at harvest can cause severe fruit dam­ age, while a low relative humidity Soil requirements reduces the incidence of fungal diseases. Light winds can be benefi­ Grapevines are adapted to a cial during summer by reducing wide range of soil types ranging [II willte" tile vinesare dorll/ol/t mid are pruned. from coarse gravelly sands to clays, A CO/l/llIOII practice ill tlte Swall Valley is to the extremes of temperature and plllllt ll ieglll1lillOlis COlIer crop ill n/temate rows. humidity. Moderate and strong a lthough they will perform better on certain soils. Soils with a loam to fine sandy loam texture are consid­ ered ideal because of their drain­ age, water-holding capacity, nutri­ ent retention and rooting condi­ tions. Preference for loams over fine sands diminishes as soil depth increases. Deep loams may stimu­ late excessive vine growth at the expense of yield and quality. Grapevines are tolerant of water­ logging during the dormant phase, although not during the growing period. If grown in soils with no impeding layers they will develop a deep (> 3 m), extensive root system. The depth of surface soil is im­ portant, as it is the most fertile part of the soi l profile. As the bulk of the vine's feeding roots are found in the top 15-60 em, the surface soil should be 30-45 cm deep or prefera­ bly 45-60 cm deep (Webber 1976a) To maximize the depth of usable surface soil, a minimum tillage system is preferred. The available soil volume is maximized, the structure is maintained or im­ proved and compaction is reduced.

LAND RESOURCES SERIES No.6 20 Hardpans induced by excessive ing a peak when the fruit is rapidly This equates over the growing sea­ traffic and shallow cultivation are a sizing, then declining after harvest. son to a water requirement of about common problem to vineyards in Sensitivity to moisture stress de­ 5000 m3/ha. Low volume micro­ the Swan Valley, resulting in root pends on the growth stage. The sprinkler or trickle systems are the and water penetration problems. most critical growth stages are preferred irrigation method. Vine Where they are relatively close to flowering, fruit set, lag phase and rows should be planted to offer the the surface they can be successfully veralson. least resistance to the prevailing ripped (Smith et al. 1969). The pres­ Three main types of irrigation wind. Wind-breaks should be used ence of an impeding layer restricts systems are used in the Swan in exposed sites. On fertile soils, root penetration, affecting the vol­ Valley; furrow, sprinkler and which resu It in vigorous vine ume of soil the roots can explore. It micro-irrigation. To improve water growth, a double sloping link trel­ can also result in drainage prob­ use efficiency, the Department of lis should be used, while, with less lems and the development of tem­ Agriculture encourages the adop­ vigorous vines, the sloping T trellis porary perched water tables. Herne tion of micro-irrigation. The water or T trellis is adequate. and Cruse soils have almost imper­ quality should preferably have a A number of varieties are recom­ vious clay subsoils in some low flat salinity level < 280 mS/m. Irriga­ mended for the Swan Valley in­ areas, resulting in poor internal tion water with an electrical con­ cluding Flame Seedless, Emperor and external drainage. Under rain­ ductivity > 280 mS/m may cause (clone 3A 2295), Sultana (clone M5), fall, impeding layers at a depth of problen1s with associated excessive Queen, !talia, Perlette, Cardinal < 1 m may cause problems unless salts and toxic levels of chloride or (clone 2290) and Ribier (I. the land is gently sloping and has sodium. When irrigating with Cameron, personal communica­ good downslope drainage. Under water of marginal quality, sprin­ tion). The recommended root irrigation, impeding layers in the kler irrigation should be avoided or stocks selected to overcome nema­ top 1-2 m often result in perched only night watering practiced. todes and drought are Sch­ water tables and the need to install With high salinity water only use warzmann, 34EM, Ramsey 1613 drains. micro-irrigation. A leaching com­ and Dogridge. The nutrient requirements of ponent should be applied to avoid On suitable soils (Class l, II, III) it grapevines are small compared a build-up of salts in the root zone. is possible to achieve average with those of more intensive horti­ yields of 25-30 kg of marketable cultural crops, partly because the Management fruit per vine, or 30 t/ha assuming prunings and leaves are returned a planting density of 1190 vines per to the soil. Each tonne of fresh The management requirements ha. The minimum viable area re­ grapes removes 0.6 kg N, 0.17 kg P are specific to the type of viticul­ quired at these marketable yields is and 2.1 kg K (Webber 1976b). Also, ture. 4.5-5 ha, providing fruit for market­ vine root systems are wide ranging ing on both the local and export in their search for nutrients and markets. Quality is at least as water. The extent to which annual Table grapes important as quantity for table fertilizer applications will be re­ This land use type refers to the grape production. The most suc­ quired depends on the inherent commercial production of irrigated cessful way of achieving prelnium fertility of the soil, vine vigour, table grapes. Traditionally, the quality table grapes is through yield and any leaching losses. The Swan Valley has been a table grape adopting the latest management allu vial soils in the Swan Valley are growing area, because of the soil techniques. These include using comparatively fertile and only light types, climate and proximity to root stocks in combination with the annual applications of macro­ both the local market and facilities new improved varieties, micro­ nutrients are recommended. On for the export trade. irrigation, wind-breaks and ade­ the sandy and gravelly soils there The soil requirements for table quate disease and pest control. should be annual applications of fertilizer based on leaf analysis. grape production are more strin­ gent than for wine grape or dried Wine grapes vine fruit production. They require This land use refers to the com­ Irrigation deep (> 75 cm), well drained soil, preferably with a sandy loam to mercial production of grapes for Irrigation requirements vary, de­ loam texture. Naturally fertile soils wine making with supplementary pending on the type of viticulture. are an advantage and do not result irrigation. In the Swan Valley, the Table grapes normally require irri­ in a loss of quality as with dried principle wine producing vine­ gation over the growing season, vine fruit. yards are located on the Belhus, while wine grapes and dried fruit Houghton and Swan series of the can be grown with supplementary The irrigation requirement for alluvial soils, on the Cruse and table grapes varies over the grow­ irrigation or on soil moisture re­ Herne series of the plain and on the ing season. The peak crop factors* serves. The crop demand for water Lotons series of the foothills. The changes over the growing season. are 0.45 on medium to heavy tex­ wine varieties Chenin Blanc, Ver­ Evapotranspiration is low at the tured soil and 0.55 on sandy soils. delho, Sermillon, Chardonnay, start of the season, but increases as Shiraz, Cabernet Sauvignon, Pedro vine foliage develops and days , Crop factor = a percentage of and Tokay are widely grown and become longer and warmer, reach- Class A pan evaporation. suited to the area.

21 LAND RESOURCES SERIES No.6 Ollt:' of flIt:' mainstays of tlte taNe grape il/dllstry ill the SIl'n1l Valley is the variety [~ed Emperor. It perforllls parfiClllarly well 011 o(1('rilend trellis.

Wine grapes can be grown on a Nematode resistant rootstock is dependent on dried fruit produc­ range of soi l types, although they required for wine grape production tion for his/ her income. The dried should preferably be moderately to and Schwarzmann, 34EM and fruit industry is based on the pro­ well drained. High soil fertility Ramsey have been successfully duction of sultanas, raisins and may adversely affect wine quality. used. Wine grapes are generally currants from Zante Currant. The fruit tends to be of a coarse planted closer than table grapes Currant vines will grow on a texture with a poorly balanced and should be trellised according wide range of soil types, but prefer composition. A variety of soil types to vine vigour. well drained soils with a friable are desirable if a winery is to make clay subsoil 30-75 em below ground a number of different wines. level. Deep, fertile loams tend to Dried vine fruit Irrigated vines will establish produce high yields of poorly more quickly than non-irrigated This land use refers to the com­ coloured watery fruit. vines, resulting in larger crops mercial production of dried vine Vines for dried fruit production during the early seasons and a fruit with supplementary irrigation can be grown without irrigation, more uniform vineyard. On suita­ during the summer. In Western although significant yield benefits ble soils in the Swan Valley, yields Australia, the main areas of dried can be achieved with supplemen­ up to 10 t/ ha for non-irrigated fruit production are the Swan Val­ tary or regular irrigation. A single vineyards can be obtained, al­ ley, Chittering Valley, Muchea and irrigation of 75 mm applied in though at this level of production Bindoon. No vigneron is wholly December increases yield by about wine quality is affected. Supple­ mentary irrigation during the early to mid-season period is beneficial. There is growing support for the view that irrigation up to veraison has no deleterious effect on wine quality and results in Significantly higher yields (jamieson 1976). A level of 15 t/ha on suitable soils lVith proper irrigation manage­ ment would give maximum results from the interaction of yield and wine quality. A minimum area of 12-14 ha is required to remain viable O. Cameron, personal com­ munications}.

The Swan Valley pl"Odllc('s sOllie filiI.' willes ami is (III imporfmlf ·wille /IInkillg (lrea w/Jere sOllie 80?c of tile Sfnfc's ·wuw is /IIadc. 1@trr("t#?s1rkfr Ix

LAND RESOURCES SERIES No.6 22 10% in an average year and 30% in Strong winds can be very damag­ and previous fertilizer history. The a dry year (1. Cameron, personal ing to the quality of the fruit. normal planting densities used to communication). Regular irrigation be 7 m x 7 m (166 trees/ hal, now (crop factor 0.4) may increase closer plantings of 2.5 m x 5.5 m Soil requirements yields by up to 50%, although there (727 trees/hal are favoured be­ may be a reduction in quality. Citrus roots have a high oxygen cause of the earlier returns ob­ requirement, so a well drained site Zante currant is the currant vari­ tained . is essential. Deep, light to medium ety presently used, although it has textured soils are preferred and the a major fault in that the berries are water table should not come within Stone fruit prone to splitting. Three Western 1.3 m of the surface. A well aera ted Australian clones (clone 5, 8 and This la nd use refers to the com­ site also lessens the problems with 10) give significantly higher yields. mercial production of irrigated PlIylopl/lOm cilroplIllIom, a major Nematode resistant root stock is stone fruit, including peaches, nec­ root pathogen of citrus. In a soil required and Ramsey has proved tarines, plums and apricots. The free of impeding layers citrus 'will to be the best. Planting densities Swan Valley is only suitable for the send down a tap-root (> 2 m). The and trellis design depend on vine production of 'low-chill' varieties. majority of the horizontal lateral vigour and irrigation. There are some stone fruit in the roots are in the top 50 cm and 90 O/C Swan Valley, mainly 'old' low-chill On well drained soils with sup­ occur in the top metre (Landon peach varieties, which have been plementary irrigation, yields 1984). Citrus can tolerate soil pH's superseded by new improved, should be between 3-6 t/ha, or up from 5-8. They will grow well on early maturing varieties. Small to 7 t/ha with regular irrigation. deep, infertile sandy soils, although plantings of the new varieties have The minimum viable area required production on the highly bleached proved successfu I. is 12-15 ha assuming yields> 2 coarse sands is marginaL With their t/ ha. Successful plantings in the lower moisture holding capacity, future will include grafting high sandy soils have the advantage of Climate yielding selections on to nematode warming up earlier in spring. Stone fruit are cool to warm­ resistant root stocks, with supple­ season crops. All stone fruit have a mentary irrigation and the adop­ Irrigation chilling requirement (i.e. a period tion of improved management "vith an air temperature of < TC) techniques. Citrus have a lower irrigation for flower initiation, although the requirement than most horticul­ actual requirement varies consider­ tural crops and are well adapted to Citrus ably. The Swan Valley has a rela­ controlling transpiration losses, tively low number of chilling This land use refers to the com­ even under windy conditions. A hours, ant;i it is only suitable for the mercial production of irrigated cit­ crop factor of 0.6 on medium to production of 'low-chill' varieties rus fruit, which includes oranges, heavy textured soils and 0.8 on of stone fruit. Peaches and nectar­ mandarins, lemons and grapefruit. sandy soils will suffice. Citrus are ines are susceptible to frosts and Citrus were once the second most sensitive to saline irrigation water the fruit is easily damaged by hail. important horticultural crop after and the irrigation water salinity vines in the Swan Valley. The level should be < 150 mS / m. Care adverse effects of wind, more prof­ must be taken if the irrigation Soil requirements itable alternative crops and compe­ water is of marginal salinity status, Stone fruit can tolerate some tition with eastern States fruit has avoiding leaf contact and applying waterlogging during the dorrnant resulted in only a remnant citrus a leaching factor. Low level sprin­ phase, although they are highly industry in the Swan Valley. This is klers or micro-sprinklers are the sensitive to waterlogging over the nolV mainly based on early man­ preferred irrigation system. growing season. Under anaerobic darins and oranges grown on root conditions, hydrocyanic acid is stock. formed in the plant from the hy­ Management drolytic breakdown of a glycoside. The main cultivars currently Stone fruit can be grown on a wide Climate (1990) grown in the Swan Valley range of soils as long as they are Citrus are a warm temperature, include Valencia and Navel or­ well drained. Plums and apricots Mediterranean crop. They are sen­ anges and the early season man­ can be grown successfully on rela­ sitive to low humidity levels and darines, Early Imperial and Em­ tively shallow soils if Marianna the optimum temperature (mean peror. Citronelle is the major root plum rootstock is used. For other daily) for growth is 23-30 'C, al­ stock used, although it is suscepti­ stone fruit and rootstocks, deep though they will still grow if the ble to the root pathogens citrus soils (> 1 m) are required. Stone temperature is in the range 13- nematode, Tylel1c1l11ll1s sellIipelle­ fruit can be successfully grown on 35 'c. Citrus are reasonably resis­ trails and Phytophthora citrophtlwm. the highly leached coarse sands tant to frosts, except in late spring. Resistant rootstocks such as Pon­ lVith careful management. They are They have no chilling require­ cims tri!olintn and Troyer citmnge responsive to plant llutrients, and ments, although they do require a should be used when replanting an regular applications of fertilizer (N, period of cool weather for proper area. Fertilizer requirements vary P, K, Mg, Cu, Zn, Mn) are recom­ colour development of the fruit. depending on the soil type, tree age mended.

23 LAND RESOURCES SERIES il!o. 6 00663·5 Table 5. Crop factors for various stone fruit over the growing season Paulin (1984)

Crop October i\ovember December January February March April

Peach-Early 0.4 0.9 1.2 1.2/0.6 0.6 0.6 0.5 -Mid 0.4 0.7 0.7/1.2 1.2 1.2/0.6 0.6 0. 5 -Late 0.4 0.7 0.7 0.7/1.2 1.2 1.2/0.6 0.5 Plum 0.4 0.8 0.9 1.0 1.0 1.0/0.6 0.5 Apricot 0.4 0.8 0.9 1.0/ 0.6 0.6 0.6 0.5

.. Crop factor = a percentage of Class A pan evaporation.

Irrigation squash) and the root crops (pota­ beans, onions and lettuce tend to The irrigation requirements for toes, carrots, parsnips and turnips). have shallow rooting patterns with stone fruit vary depending on the Market gardening has taken a sup­ most roots concentrated in the top planting density, tree spacing, age, plementary role to grape growing 30-50 cm. Cucumbers, peppers, soil type, cultivation practice and in the Swan Valley with many peas (tap-root), water-melons and variety. The crop factors for stone vignerons supplementing their in­ tomatoes have root systems which fruit vary from 0.4-1.20 depending come from grapes with small mar­ develop to a depth of 1-2 m, with on the crop type and earliness or ket gardens. The most common the main nutrient and water uptake lateness of the variety (Table 5). crops grown are water-melons and roots reaching a depth of about Stone fruit are salt sensitive and rockmelons, with about 50 ha culti­ 70-120 cm (Landon 1984). irrigation wa ter of < 80 mS / m vated annually. Other crops includ­ ing pumpkins, cauliflowers, toma­ should be used. Sprinkler, trickle Irrigation and micro-sprinkler irrigation can toes and cucumbers are grown on a all be used, although the latter is small scale « 3 hal. The irrigation requirements for the most satisfactory on sandy soils vegetable crops are generally under conditions of high evapora­ higher than for other horticultural tive demand. Climate crops. The crop factor for mature There is a whole range of vegeta­ crops grown on sandy soils va ries from 1.2-1.5 evaporation replace­ ble crops which vary from cool to Management wa rm season. Most crops could be ment. Vegetable crops are often Peaches and nectarines are sus­ grown in the Swan Valley for at grown on sandy soils with low ceptible to nematode infestation least part of the year (Moore 1990). water-holding capacity and, under (root-knot nematode, Meloidogylle The cole crops are cool climate conditions of high evaporative de­ spp. and root lesion nematode, crops and can withstand sub-zero mand, same two to three waterings Pmtylenclitls spp.), and they should temperatures. The cucurbits are per day may be required. Vegetable be planted on resistant root stock. warm season crops and prefer crops have a wide range of toler­ Soil and root treatment is necessary mean temperatures in the range ance to irrigation water salinity for diseases such as armillaria and from 18-30'C. The seed does not levels. Parsnips, green beans, celery crown gall which cannot be con­ germinate below about 15'C and and cucumber are salt sensitive and trolled by root stocks. High density the plants are susceptible to frosts require water of < 80 mS / m, while planting systems, with or without and cold winds. The climatic re­ broccoli, tomatoes and artichokes trellis, are favoured for stone fruit. quirements for root crops vary can tolerate up to 230 mS /m. Over­ These systems result in higher considerably, al though most prefer head sprinklers are used to irrigate yields per unit area than traditional cool to temperate conditions. vegetable crops, while the fruit planting systems and the crop ma­ crops (tomatoes, water-melons, tures earlier, giving a significant rockmelons, cucumber) can be irri­ commercial advantage. Soil requirements gated with low volume trickle sys­ tems, resulting in substantial water A well drained site is a require­ savings ment for most vegetable crops. 00-25%). Market gardening Root crops also require a loose, or This land use refers to the year friable topsoil and a moderately Management round, commercial production of deep to deep soil. The high levels of vegetable crops and includes a nutrients applied as organic ma­ Management vanes depending large number of plant species with nures and inorganic fertilizers re­ on the crop. a range of requirements. Many duce the advantages of using natu­ vegetable crops can be grouped rally fertile soils. Vegetable crops together; cole or brassica crops tend to be relatively shallow rooted (cauliflower, cabbages, Brussels compared with other horticultural sprouts and broccoli), cucurbit crops, although rooting depths crops (cucumbers, rockmelons, vary considerably between species. water-melons, pumpkins and Vegetables such as cabbages,

LAND RESOURCES SE RIES No.6 24 Lotons series ing conditions result in this soil type being unsuitable for horticul­ Soils and land use Description: ture. limitations Well drained lateritic, duplex Range sa nd (deep phase); The soils with light textured A horizons coarse sandy A horizon continues (medium to coarse sand to sandy to a depth of over one metre, and loam) containing large amounts of there is minimal gravel in the loose, ferruginous gravel overlying profile (Pym 1955). a yellow mottled sandy clay. The gravel layer may be quite thick (> 1 Limita tions: m) and may be overlaid by a gravel-free layer of sand with or­ The internal drainage of Range ganic matter. There are a number of sand and gravelly sand is restricted different soil types and phases in because of the shallow clay subsoil the Lotons series; these soils are and its low permeability. Site similar for horticulture and have drainage depends on the slope, been grouped for the land capabil­ with lateral movement on sloping ityassessment. sites. Soil depth limits production on these soil s except for the deep Limitations: phase. Generally few significant limita­ tions, although the sandy A hori­ Recommendations: zon has a low moisture holding The Range seri es has low suita­ capacity, and the high gravel con­ bility for horti cu lture because of tent means applied phosphorus is the restricted rooting conditions. readily fixed. The high gravel con­ Range sa nd (deep phase) has a tent also reduces the soil volume. greater rooting depth, although The surface soil is quite wind production is limited by the low erodible, particularly Lotons sand. water-holding capacity and short­ The main limitation in the foothills age of groundwater for irrigation area where this soil series is found as this soil series is found in the is the general shortage of ground­ foothills. water.

Recommendations: The Lotons soils with character­ istics of good drainage and physi­ Oakover series cal conditions are suitable for wine grape production. Distinctive qual­ Description: ity wine can be produced, but only Red-brown, moderately well low yields are achieved. These soils drained duplex soils. A typical are marginally suitable for table profile has a brown, coarse loamy grapes and dried vine fruit because sand to coa rse sa ndy loam surface of their limited water-holding ca­ texture over a brown, yellow­ pacity, shortage of groundwater brown to red, mottled sandy clay and wind exposure. The soils are subsoil at 30-60 cm. The A horizon suitable for other types of horticul­ frequently contains substantial ture, although the potential is se­ amounts of loose, ferruginous verely reduced by the limited gravel and or quartz fragments. groundwater. The subsoil does not impede root growth and these soils are the most fertile of the foothill soils. There are Range series a number of soil types and phases in this series, although they gener­ Description: ally have similar characteristics for Duplex soils with grey, coarse horticultural production. sand over a yellow, mottled, coarse, sandy clay at about 20-40 Limitations: cm. The A horizon may contain Few limitations with this series, ferruginous gravel and quartz frag­ although some areas may be wa­ ments. terlogged for short periods during Phases: Range sand (shallow the winter. On sloping sites, drain­ phase); subsoil encountered at a age is improved through lateral depth of 5 em. Drainage and root- movement.

25 LAND RESOURCES SERIES No.6 Recommendations: land by mounding the topsoil and (Smith ef "I. 1969), impeding root Soils of this series are moderately installing a drainage system (i.e. development and possibly accentu­ \vell drained, reasonably fertile and spoon drains). Mangin sand (deep ating any waterlogging. phase) is marginally suitable for have good physical characteristics Recommendations: and are suitable for wine grape market gardening, citrus and stone production. Distinctive high qual­ fruit production provided an ade­ Suitability of Herne series soils ity \vine can be produced, how­ quate water supply is available. for horticulture depends on the ever, yields are lower than on the drainage status which varies, as alluvial soil s. Table grape produc­ explained previously. Drainage can tion is only marginal because of the H erne series be improved by mounding the topsoil and installing drains to strong winds encountered in the Description: foothills area and the shortage of remove excess water. With natu­ groundwater for irrigation. The ex­ The Herne series consists of vel­ rally adequate or improved drain­ posed situation and limited low duplex soils which may tend age these soils are suitable for the ground water resources severely towards a gradational profile. production of wine grapes, dried limit the potential for other forms There is a light textured A horizon vine fruit and, with good manage­ of horticulture. (sand to sandy loam) of variable ment, table grapes. Provided the depth overlying a yellow, mottled drainage is adequate, then the soils medium clay subsoil. This series is are suitable for market gardening, Mangin series characterized by a fine clay layer in citrus and stone fruit. Herne sa nd the subsoil at varying depths from (deep phase) is marginally suitable Description: 70-170 cm (Pym 1955). Drainage is for market gardening. High salinity Duplex soils with a light textured impeded by this layer resulting in a of the irrigation water results in a A horizon (coarse sand to coarse perched water table during the leaching requirement to avoid salt sandy loam) overlying a massive, winter (Cv. Malcolm, unpublished build-up in the soil. cemented, grey or yellow, mottled data). External drainage of the sandy clay. Ferruginous gravel Herne soils is generally limited, may be present in both the A and B although dissection in some areas horizons. The cemented subsoil im­ (mainly those nearest the Swan Cruse series pedes root development and re­ River and other streams) does Description: sults in a perched water table. allow some movement in this man­ Yellowish brown duplex soils Phases: Mongin sand (swampy ner. The likelihood of waterlogging depends on the depth of the A with a light textured A horizon. phase); The poorly drained areas of The surface soil is massive with a the Mongin series. Unsuitable for horizon, the depth to the fine clay loamy sand to sandy loam texture all forms of horticulture. layer and the structure of the upper B horizon. overlying a yellowish brown, mot­ Mongin sand (deep phase); A tled medium clay. The Cruse series transitional soil type between the Phases: Herne sand (deep is similar to the Herne series, al­ normal Mongin series and the aeo­ phase); A transitional soil between though it can also be a transitional lian series (Pym 1955). A typical the duplex plain soils and the soil between the Herne series and profile has 0.6-1.0 m of coarse light aeolian soils (Pym 1955). The typi­ the alluvial soils (Pym 1955). As grey sand over a massive, mottled, cal profile consists of a light grey with the Herne series, the Cruse sandy clay' subsoil. sandy Al horizon stained with series has variable site drainage organic matter, followed by a con­ status, ranging from moderately Limi ta tions: spicuously bleached A2 horizon well drained to imperfectly Site drainage is the overriding overlying a clay subsoil at a depth drained. influence on vine performance and of one metre. horticulture on these soils. The Herne sand (brown phase); Limitations: cemented nature of the subsoil Herne soils with a brown coloured Drainage is the major limitation results in a shallow effective soil topsoil and often containing a sig­ for irrigated viticulture on most depth. These soils have a low nificantly higher clay content. Vine areas of the Cruse series. nutrient status and can be subject to performance on these soils is salinization. slightly superior to that on other Recommendations: Herne sands (Pym 1955). The recommendations for the Recommendati01l5; Cruse series generally lollow those Waterlogging during winter and Limitations: for the Herne series. Drainage may spring severely restricts horti­ Site drainage would be the major be necessary in some areas, other­ cultural production on the Mangin limitation for viticulture on most of wise the soils are suitable for all series, apart from Mangin sand the Herne series, although it does forms of viticulture. Cruse clay (deep phase). These soils were once vary. The extent of waterlogging loam has a greater water-holding used extensively for currant and damage depends upon the dura­ capacity and nutrient status, al­ wine grape production, although tion of the perched water table and though it is not as easily cultivated declining yields have seen most of the depth of unsaturated soil above as the lighter textured soils. The the land revert to pasture. Produc­ it. Traffic hardpans can develop in deeper, well drained Cruse series tion can be improved on marginal Herne sand at a depth of 10-20 cm would be suitable for tree crops,

LAND RESOURCES SERIES NO.6 26 while the soils with light textured Limitations: Limitations: A horizons could be used for mar­ These soils have excellent phys­ These soils have excellent phys­ ket gardening. ical and chemical characteristics ical and chemical characteristics \·vith only minor limitations. They with only minor limitations. are slightly excessively drained (Pym 1955) and a hardpan can Recommendations: Swan series develop in these soils at about 20 on. Ideal for table grape production, Description: also suitable for citrus, stone fruit and market gardening. The high Alluvial soils situated on the Recommendations: soil fertility reduces the quality of general level of the Swan Coastal These soils have excellent phys­ wine grapes and dried vine fruit. Plain. Distinguishing features are icC'd and chemical characteristics, the well developed B horizons and although internal drainage is their red colour (Pym 1955). The slightly excessive. This can be over­ sand fraction is micaceous. come with good irrigation manage­ Pyrton series Swan sand; Reddish brown du­ ment and causes no limitation. plex soils \·vith a deep loamy sand Highly suitable for table grapes, Description: A horizon. stone fruit, citrus and wine grape Recent alluvial soils formed on production. These soils are too Swan sandy loam to clay loam; the floodplain of the Swan River; fertile for dried vine fruit produc­ Brown to red duplex or gradational soil profiles are highly variable and tion and the berries tend to be soils. The topsoil has a sandy loam consist of bands of alluvium, often watery and of poor quality. to clay loam texture with a massive vlith a high coarse sand content. structure and is about 15 em thick. These are fertile soils with mediul11 The subsoil texture varies from a to heavy surface textures (loam, clay loam to a medium clay and has clay loam, clay), except for Pyrton an earthy fabric. sand. The latter is a result of a Belhus series recent deposit of coarse alluvium Limitations: over a Fyrton loam to clay loam Description: A minor limitation on the flat (Pym 1955). areas is slightly impeded drainage Soils formed on the older allu­ through the subsoil, otherwise ex­ vium and which occur on the Limitations: cellent soils with desirable physical upper terraces; soil profiles are and chenlical attributes. similar to the Houghton series, The flooding hazard is the main although B horizons are more de­ limitation and these soils can only Recommendations: veloped. A typical profile is a dark be cultivated over a narro'w mois­ The S,van series are suitable for brown loamy sand A 1 horizon ture range. Consequently, correct all the types of horticulture. The B gradually increasing in texture to timing of operations is imperative. horizon may impede the percola­ sandy clay loam at depth. These tion of wa ter to some extent with soils have a massive structure with Recommendations: the development of a plough pa n, an earthy fabric, and there is no The Pyrton series is generally although this condition can be restriction to root development. suitable for table grapes, wine readily reversed.

Houghton series

Description: Soils formed on the older allu­ vium and which occur 011 the first terrace are mixed with the Belhus series 011 the higher levels (Pym 1955). A typical profile is a uniform yellowish red, micaceous sand to loamy sand with a massive struc­ ture. These are deep soils with no restriction to root development.

Depnrtlllwt of Agriwlture rescnrch ill tlie Swnn Vlllley illc/lldes prodllctioll of alit of seasoll tll/J/e grapes (/lid trinls lIsing Ilew varieties.

27 LAND RESOURCES SERIES No.6 grapes and dried vine fruit. Other forms of horticulture, except for sun1mer market gardening, are precluded by the flooding hazard.

Karrakatta series Description: Deep uniform sands of aeolian origin, these soil s are well to ra p­ idly drained and predominantly occur as low rises on the western side of the Swan Ri ver. A profile typically consists of grey sand with organic matter (0-30 em) over yel­ low sand. Phases: Karrakatta sand (grey phase); Light grey A2 horizon to 0.5-1.0 m over yellow sand.

Limitations: Moisture holding ca pacity and the low nutrient retention are the main limitations of these deep sandy soils. They are also highly wind erodible, particularly if in an exposed situation. The Karrakatta sand (grey phase) is less fertile and has a lower water-holding capac­ ity.

Recommendations: Karrakatta sand is marginally suitable for table grape and wine grape production, while the grey phase is not suitable. Provided there is a plentiful supply of groundwater, the Karrakatta sand can be quite productive for citrus, stone fruit and market gardening. The lower nutrient status and water-holding capacity of the Kar­ rakatta sand (g rey phase) results in it not being suitable for citrus production and only marginally suitable for stone fruit and market gardening.

LAND RESOURCES SERI ES No.6 28 Viticulture is the most important are generally suitable for viticul­ industry in the Swan Valley and it ture, particularly wine grapes, al­ Discussion is anticipated that it will maintain though the scarcity of groundwater its importance. Research, extension and wind exposure limit the de­ and development need to be en­ velopment potential for table couraged to continue improving grapes. The deep, rapidly drained the viability of viticulture and its aeolian sands are suitable for mar­ C0111petitiveness. An expansion of ket gardening, citrus and low chill the citrus industry is not antici­ stone fruit and marginally suitable pated because large areas of citrus for viticulture. Those aeolian soils are being planted elsewhere on the found in low lying poorly drained Swan Coastal Plain and on the areas are not suitable for horticul­ Dandaragan Plateau to the north. ture. It is unlikely that large scale However, there is a place for low­ horticulture development will take chill stone fruit in the Swan Valley place on the aeolian soils because within the corridor of horticultural the groundwater is primarily re­ soils. Market gardening will con­ served for future public water sup­ tinue, predominantly as a supple­ ply (Gnangara Mound). Potential mentary source of income for vign­ problems with fertilizer pollution erons. Stone fruit and market gar­ of the groundwater may arise in dening both have irrigation crop addition to competition with urban factors in the order of two to three land use. times that for table grapes, which The alluvial soils of the Swan may limit their expansion in an Valley (Swan, Belhus, Houghton area with limited groundwater soil series (Pym 1955), plus most of supplies. the Herne and Cruse soil series of The land capability assessment the plain, are highly productive shows a corridor of suitable horti­ horticultural soils because of their cultural land in the Swan Valley, physical and chemical characteris­ Adoptioll of lIew technology (such (IS link trellis ), flanked in the east by poorly tics. These soils are a scarce re­ (llld production of varieties demanded by COI/­ drained Mongin soils and to the source in Western Australia and SlImers, are important consideratiol/s if tile table grape illdustry ill the SWIlII Vlllley is to remlliH west by aeolian soils. On the foot­ are of particular value because of villble. hills of the Darling Scarp the soils their location close to Perth. Most of the soils within the Swan Valley Rural Zone have a capability rating of Class I to Class III for horticul­ ture.

Prime agricultural land ·The State Planning Commis­ sion's 'Rural Land Use Planning Policy' includes the requirement to discourage the removal of prime agricultural land from agricultural production and to prevent adverse effects on the viability of estab­ lished agricultural industries (Anon. 1988). Prime agricultural land in West­ ern Australia may be defined as "that land which occurs where the agronomic factors (e.g. soils and management) and environmental factors (e.g. climate, water quality and availability) combine so that the 'value to society' from agri­ culture is greater than the value from alternative uses of the land" (Read 1988). The value of land to society comprises both monetary and ex­ ternal values. The value of agricul­ tural land includes its significance

29 LAND RESOURCES SERIES No.6 for the continuity of supply of a production, so the present Swan ditional research staff and intro­ product to domestic and export Valley Rural Zone boundaries are duction of new table grape varie­ markets (Read 1988). appropriate. Renaming the S\van ties has given the viticultural in­ Valley Rural Zone as a 'special dustry impetus to expand. Other The Swan Valley CClIl be consid­ ered prime agricultural land be­ horticultural zone' would facilitate incentives that have been made cause: its recognition as a special purpose available, such as the preferential zone. Land use control, if table rating system, power cost conces­ 1. The Swan Valley is a proven grape production is to be promoted sions and ensuring adequate water area with respect to climate within this horticultural zone, supplies, improve the viability of and soils for the production of needs to be more stringent than at vi ticulture. premium quality table grapes present. A strict water allocation and is the major production policy may be one means of achiev­ On soil types Class IV to V, but area for table grapes in West­ ing this goal. still within the horticultural zone, ern Australia, supplying 95- alternative agricultural practices 99% of the domestic market, in In the Shire of Swan's Town should be encouraged, provided addition to exports worth = Planning Scheme No. 9 (Section that neither the use nor potential 50.5 million annually. 8.2.2) the term 'prime agricultural use of adjacent Class I, 1I and III soils nor the rural character and 2. land', previously referred to as We believe the value to society high quality horticultural soils, amenity of the area is adversely of the viticulture industry in should now refer to land which is affected. Alternatively, on these the Swan Valley goes beyond suitable for horticulture, compris­ Class IV and V soil types tourism, its direct economic value. The ing classes l-lll as determined by recreation and cottage industries afea is an important tourist, the authors (Figure 8). It includes use should be allowed where such recreational and heritage area. the Swan, Belhus, Houghton, uses have the potential to enhance It is a popular destination for Pyrton, Herne and Cruse soil series and add to the purpose of the day trips from Perth and much (Pym 1955). horticultural zone. of its charm lies in the aesthetic If land east of the standard gauge rural setting provided by the 'Land not considered suitable for horticultural use', refers to land railway and west of West Swan vineyards. with a Class IV and/or Class V Road is to be zoned urban as capability rating for most horticul­ proposed in the review of the Future land use implications tural crops (i .e. the area not shaded Corridor Plan for Perth, (Anon. in Figure 8). 1987), then significant buffer zones The area of prime agricultural of low intensity rural-residential land in the Swan Valley is about Within the horticultural zone, development are essential to re­ 3400 ha, which is sufficient to form horticultural pursuits, particularly duce the speculative development the basis of a viable and expanding viticulture, should be encouraged pressure on the horticultural zone. viticultural industry. However, on the Class I-III soils. Incentives Buffer zones of 0.5-1 km wide, competing and conflicting land use should be given to maintain the would be adequate to minimize the demands have the potential to viticultural industry already pre­ development pressure within the erode the viability of the horticul­ sent and to encourage its expan­ relatively small and narrow horti­ tural industry unless adequate land sion. The incentives already used, cultural zone. A narrow corridor of use and subdivisional controls are such as promotion, inspection, ad- rural-residential use would also maintained. There is a need to accept the Swan Valley Rural Zone as a special horticultural area with a set of explicit policies dealing with appropriate and inappropri­ ate land uses. The Swan Valley Rural Zone referred to here gener­ ally includes most of the prime agricultural land for table grape

High qllality clay, (/ scnrcc !wturnl /"(':'Ollr(l.', is fOlllld ill Ille SW(/II Valley wilerI' a COli/pet illS 1m/If lise is file c1nlj extraction indllstnr HOit'­ epCl", this inrillstr!i is I/Ot colllpatible'l{'iflt all other lalllt lt~e5 ill tlte Swall VallcJ/.

LAND RESOURCES SERIES No.6 30 km

Prime Horticultural land

_. _. _ Swan Valley Rural Zone

main road

r,uiway

~-~ riwr. cr('{'k

Figure 8. Location of the Swan Valley Rurai ZOlle ill reiation to prime hortiCilituralland for table grape production (Class I, II, Ill)

31 LAND RESOURCES SERIES No.6 reduce potential conflicts and off­ With zoning, horticulture and site impacts (dust, spray drift) be­ particularly the viticultural indus­ tween land uses. try will be in a better position to There are still viable viticultural remain, and expa nd . With good and horticu ltural enterprises exist­ planning, tourism and recreational ing outside the horticultural zone pursuits can also be developed. and within the rural living zone. With some control, the recreational The presence of these enterprises and tourism pursuits will add to reduces the pressure on the horti­ the character of the Swan Valley. In cultural zone because, in effect, it addition, there will be a place for makes the horticultural zone seem rural and residential li ving. larger. For this reason it is impor­ tant to maintain these enterprises. If they are subject to the same incentives and concessions to those in the horticultural zone, it will help maintain viability and relieve pressure on the horticultural zone. The authors believe that the area just outside the horticultural zone, but within the rural living zone, would be ideal for the develop­ ment of tourism and recreational pursuits. Permission should only be given to those pursuits that add to the rural character of the Swa n Valley. There is limited prime horticul­ tural land east of the railway line, but there are pockets of suitable soils, particularly for wine grapes. The better soil types are the Oak­ over and Lotons soil series (Pym 1955). Existing commercially viable vineyards on such foothill soils should be protected for horticul­ ture by an appropriate zoning and separated from future urban devel­ opment by rural-residential buff­ ers, as described. A subject for further discussion is clay excavation, which is not com­ patible with the maintenance of prime agricultural soils or with horticulture in the horticultural zone. It is generally not compatible with other uses in the Swan Valley, such as tourism. The Department of Agriculture is conducting re­ search on the success of clay mine site rehabilitation for viticulture. Clay excavation could be consid ­ ered in the rural-residential zone. If clay excava tion is carried out in this area then the land should be reha­ bilitated to a standard appropriate to support urban and rural­ residential uses.

LAND RESOURCES SERIES No.6 32 The authors thank: Mr l. Cameron, Senior Technical Officer with the Acknowledgements Department of Agriculture, for as­ sisting with the determination of the land capability ratings. Staff from the Division of Horticulture and Division of Resource Manage­ ment for constructive criticism of the manuscript/ in particular Ms R. Oma. Mr R. Hulajko for technical assistance in the field and Mr R.A. Sommerville for preparation of the figures in this report. Mr C. Dim­ mock for providmg access to de­ tailed site data from the CSIRO Soil Archives. The CIS group of the Department of Agriculture for preparation of the maps and the Swan Valley Policy Committee for financially assisting the cost of map production. The Cadastral base map used in Figures 2, 4, 7 and 8 is from the Department of Planning and Urban Development.

33 LAND RESOURCES SERIES No.6 Allen, AD. (1980). The hydrogeology of the Swan Valley Area and results of monitoring. Western Australia Geological Survey Hydrology References and bibliography Report No. 2253. Anon. (1985). Swan Valley policy. The Government of Western Australia, September 1985. Anon. (1986). Swan Groundwater Area, pasture survey. Unpublished report by the Water Authority of Western Australia. Anon. (1987). Planning for the future of the Perth Metropolitan Region, State Planning Commission. Anon. (1988). Policy DC 3.4. Rural land use planning policy, State Planning Commission, March, 1988. Bagnold, R.A. (1941). Physics of blown sand and desert dunes. Methuen and Company Ltd., London. Banyard, R.E. (1985). Swan Groundwater Area, Groundwater Allocation Policy. Unpublished report by the Water Authority of Wes tern Australia. Church ward, H.M. and McArthur, W.M. (1980). Landforms and soils of the Darling System Western Australia. In 'Atlas of natural resources, Darling System W.A.'. Department of Conservation and Environ­ ment, W.A. Food and Agriculture Organization of the United Nations (1979). Land evaluation criteria for irrigation. Report of an expert consultation, Rome, February 27 to March 2, 1979. World Soil Resources Reports No. 50. FAO, Rome. Food and Agriculture Organization of the United Nations (1983). Guidelines : land evaluation for rainfed agriculture. FAO Soils Bulletin No. 52, Soil Resources Management and Conservation Service. Land and Water Development Division, FAO, Rome. Hooper, D.A. (1986). Swan Groundwater Area, groundwater allocation policy and management study. Unpublished report by the Water Resources Management Branch, Water Authority of Western Austra­ lia, November 1986. Houghton, P.O. and Charman, P.E.Y. (1986). Glossary of terms used in soil conservation. Soil Conservation Service of New South Wales. Jamieson, W.R. (1976). Viticulture principles and practice in Western Australia. Proceedings of a seminar held jointly by the University of Western Australia Country Extension Service and the Western Australian Department of Agriculture, Present status and future prospects. Busselton, December 1976. King, P. and Wells, M.R. (J 990). Darling Range rural land capability study. Western Australian Department of Agriculture, Land Re­ sources Series No.3. Landon, J.R. (Ed.) (1984). 'Booker tropical soil manual'. A handbook for soil survey and agricultural land evaluation in the tropics and sub-tropics. Booker Agriculture International Ltd. Malcolm, C. V. Western Australian Department of Agriculture file no. 2738/EX (unpublished). McDonald, RC., Isbell, RF., Speight, j,G" Walker, j., and Hopkins, M.S. (1984). 'Australian soil and land survey field handbook'. Inkata Press, Melbourne. Moore, G.A. (1990). Potential for horticulture on the Swan Coastal Plain, Stage 1: Moore Ri ver to Dunsborough. Division of Resource Management Technical Report No. 105. Western Australian Depart­ ment of Agriculture. Nesic, G. (1987). Proposed Swan Valley horticultural land use and subdivision for State Planning Commission (unpublished).

LAND RESOURCES SERIES No.6 34 Northcote, K.H., Bettenay, E., Churchward, H.M. and McArthur, W.M. (1967). Atlas of Australian soils, explanatory data for Sheet 5. Perth-Albany-Esperance Area. CSIRO and Melbourne University Press, Melbourne. Olmo, H.P. (1956). A survey of the grape industry of Western Australia. Vine Fruits Research Trust, Perth. Paulin, R. (1984). Fruit tree and vine crop irrigation. Western Australian Department of Agriculture, Manjimup Bulletin MA26. Pym, L.w. (1955). Soils of the Swan Valley vineyard area. CSIRO Division of Soils. Soils and Land Use Series No. W. /, Read, V.T (1988). The concept of prime agricultural land-a Western Australian perspective. Division of Resource Management Division, Western Australian Department of Agriculture, Technical Report o. 72. Smith, S.T, Stoneman, TC. and Malcolm, c.v. (1969). Cultivation and traffic hardpans in Swan Valley vineyards. Western Australian Department of Agriculture, Technica l Bulletin No.1. Smith, S.T and Watson, j.E. (1948). Soil survey of Midland junction. Western Australian Department of Agriculture (unpublished). Steen, W.E. (1984). Swan Groundwater Area availability. Allocation and monitoring of ground water resources. Public Works D epartment of Western Australia, Water Resources Branch Report No. 101. Webber, R.Tj. (1976a). The influence of climate and soil upon wine grape production and their importance in site selection. Proceed ings of a seminar, Present status and future prospects held jOintly by the University of Western Australia Country Extension Service and the Western Australian Department of Agriculture, Busselton, December 1976. Webber, R.T). (1976b). Irrigation and drainage. Proceedings of a seminar, Present status and future prospects held jOi ntly by the University of Western Australia Country Extension Service and the Western Australian Department of Agriculture, Busselton, December 1976.

35 LAND RESOURCES SERIES NO. 6 Abbreviations in Appendices 1, 3 and 4

Existing land use Land capability ratings V Viticulture I Very high capability for the stated land use G Crazing, hobby farming II High capability o Orchards III Fair capability E Extractive industries IV Low capability V o capability Symbol Land quality (No. of values) The letters following the class symbol indicate the limiting land Site drainage (6) qualities. A range of capability values for a unit indicates variable m Moisture holding capacity (6) soil types or landform within that unit. (The land ca pability n Nutrient availability (5) classification system is explained in the methodology. The land use Rooting conditions (5) types are described in the land use requirements section.) y 5..linity hazard (5) f Flood hazard (4) q Potential for mechanization (5) k Soil workability (3) w Wind erosion hazard (6) e Water erosion ha zard (5) s Soil structural decline hazard (3)

LAND RESOURCES SERIES No.6 36 Land capability classes Appendix 1.

Table AI.1. Summary table with capability classifications for all map units

Land use type Map unit Description Existing land use Table Wine Dried Citrus Stone Market grapes grapes fruit fwit gardening

Soils of the Swan Valley vineyard area, W.A. (Pym, 1955) (A) Soils of the Darling Scarp Face Rocky and skeletal G Vr Vr Vr Vr Vr Vr Type E (unnamed) Shallow brown loam to clay loam over G Vr Vr Vr Vr Vr Vr rock

(B) Soils of the foo thills Lolons series Well drained duplex soils with a gravelly G,V li lT IIr IIlm IIr II r IIr sand A horizon

Range series Gravelly, yellow mottled duplex soils G,V IVr lVr lVr Vr IVi IVri

Range sand Subsoil encountered at approximately G Vr Vr Vr Vr Vr Vr (shallow phase) Scm

Range s(lnd Deep duplex soils with a sandy A G,V IVm lVm IVm IVi IVi IVi (deep phase) horizon

Oakover series Red-brown, moderately well drained, G,V 1I -lIIir IIrn Unrm lII i 1I-lIIi IIIr duplex soils

(c) Soils of the Plain Mongin series Duplex soils with a light textured A G,V Vri IVir rVir Vi IVi IVri horizon over a cemented, clay subsoil

Mongin sand The poorly drained areas of the Mongin G Vi Vi Vi Vi Vi Vi (swampy phase) series Mongin sand Light grey sand over clay at depth G'(O) III-[Vi lIIiwm lII-IVinm IVi IVi I IIi (deep phase)

Herne series Yellow duplex soils with light textured A V,G 1l-I1Iir I-lIIir Us-llIi IVri llli I Hir horizons

Herne sand Light grey sand over clay at approxi- G,V,O lIIir IIImhv 1II-IVim IVi IVi lIIi (deep phase) mately 1 metre depth

Herne sand Yellow duplex soils with a brown A V,G Il-Illir IIrw I1rs IlIi lIli llir (brown phase) horizon

Alluvial fan suite 1 Grey, gritty sand and mottled gritty clay G,(V) Vi IV-Vi Vi Vi Vi Vi

Alluvial fan suite 2 Brown layer of sand, sandy loam, clay G Vi [V-Vi Vi Vi Vi Vi and grit

Bellevue series Poorly dra ined, yellow mottled duplex G,E Vi Vi Vi Vi Vi Vi soils

Gilgai complex Gilgai microrelief with soils similar to G Vi Vi Vi Vi Vi Vi Bellevue series

Andrew series Poorly drained, brown duplex soils E Vi Vi Vi Vi Vi Vi Cruse series Yellowish brown duplex soils with a V,G II-IVi r Il-IVi IIr-IVi IVi 1II-IVi II-I Vir light textured A horizon

Drainage line Wet complex soils G Vi Vi Vi Vi Vi Vi complex

37 LAND RESOURCES SERIES No.6 Appendix 1. cOlllillued

Land use type Map unit Descri ption Existing land use Table Wine Dried Citrus Stone :v1arket grapes grapes fruit fruit gardening

Solonchak Saline soils Vy Vy Vy Vy Vy Vy (unnamed)

Clay pans G Vi Vi Vi Vi Vi Vi

(0) Alluvial soils Swan sand Reddish brown duplex soils with a V,G,O 1-lliws IIw Tin IIi IIi [[is micaceous sandy Al horizon

Swan sandy loam/ Reddish brown duplex soils V,G,O I-llis I-lis lIn II -Wi IIi IIis clay loam

Belhus sand Dark brown loamy micaceous sand, V,O lin II-lIIn texture becoming fi~er with depth

Houghton series Deep, yellowish red micaceous sands V,G,O Ilmw Ilmw 1I-lIln I-11m

Pyrton series Recent alluvium with dark brown G,V IlIf 1I-llIfn lI-lIlfn Vf Vf IVkf micaceous layers over sandy layers

Pyrton sand Coarse sandy AI horizon G IIIf III-1Yf llIf Vf lIl-lVf IVf

(E) Aeolian and miscellaneous soils Karrakatta sand Deep, uniform yellmv sands G,(O,V) IIIm IIIm IVm Jlmn limn

Karrakatta sand Deep, light grey sand over yellow sand G IV-Vm IV-Vm IV-Vm IIImn II-Illm IImq (grey phase)

Muehea sand Deep, light grey sands G,(V) VOl Vm VOl IVmn IIImn 11I-IVm

Barrett sand Poorly drained light grey sands with G Vi Vi Vi Vi Vi Vi organic hardpan B horizon

Bibra sand Poorly drained, light grey organic G Vi Vi Vi Vi Vi Vi stained sands

Environmental Geology Series, Muchea Sheet (1 : 50 000) 510 Rapidly drained, deep light grey sands lV-Vm Vm Vm IVmn II1mn 111m

512 Deep, uniform yellow sands IIImw IIImw lVm II-Illmn lImn 11m

Msgi IIIr IIrs IImrs IIIi IIIi IIr

LAND RESOURCES SERIES No.6 38 Land qualities assessed for each map unit Appendix 2.

Ta ble A2.1. Summa ry table of land qualities for all map units

Map Unit Site Moisture Nutrient Rooting Salinity Rood Soil Potential Wind Water Soil drainage holding retention con d i - hazard hazard workabil- for erosion erosion structural capacity lions ity mechaniza- hazard hazard decline tion hazard (i) (m) (n) (r) (y) (0 (k) (q) (w) (e) (s)

Soils of the Swan Valley vineyard area, w.A. (Pym, 1955) (A) Soils of the Darling Scarp face Rocky and skeletal Very low Poor Low

Type E (unnamed) Low Poor 10 Low fair

(8) Soils of the foothills lotons series Well drained Moderate Very low Good Nil to low Nil to High Very high Moderate Very low low to low very low Range series Moderately Moder- Very low Fair Nil to Nil to High High to Moderate Lo"" Low well to imper- ately low low very low very high to high fectly drained

Range sand (shal- Imperfectly Low Very low Poor High Nil to High High High Lo\v un\, low phase) drained very low

Range sand (deep Imperfectly Low Very low Good to Nil to Nil to High Very high High Very low Low phase) drained very low very low good

Oakover series Moderately Moderate LO\v to Good to Nil to Nil to High Very high Moder- Very low Lo\v well drained to moder- moderate very low very low ately low ately high good to moder- ate

Soils of the plain Mongin series Imperfectly to Moder- Very low Poor to Moder- Nil to Moderate Very high High Very low Low poorly drained ately low to 1m\' fair ate to very low to high high

Mangin sand Poorly drained Low Very low Poor Moder- Nil to Moderate Very high High Very low Low (swa mpy phase) to low ate to very low high

Mangin sand Imperfectly Moder· Very low Good to Moder- Nil to High Very high Very high Very low Moderate (deep phase) drained ately low very ate very low good

Herne series Moderately Moder- Low to Good Low to Nil to Moderate Very high High Very low Moderate well to imper- .tely high moderate high very low feetly drained

Herne sand (deep Imperfectly Moderate Very low Good to Nil to Nil to High Very high High Very low Moderate phase) drained to moder- to low very low very Jow ately low good

Herne sand Moderately Moderate Low to Good Nil to Nil to High Very high High Very low Moderate (brown phase) well d rained moderate low very low

Alluvial fan suite 1 Poorly drained Low to Very low Good Low to Low Moderate Very high Moderate Very low Low moder- tolo\\' high ately low

Alluvial fan suite 2 Poorly drained Low to Very low Good Low to Low Moderate Very high Moderate Very low Low moder- to low high ately low

39 LAN D RESOURCES SERlES No.6 Tab le 2. cOl1til1ued

Map Unit Site Moisture Nutrient Rooting Salinity Flood Soil Potential Wind Water Soil drainage holding retention con d i - hazard hazard ' ..'orkabil- for erosion erosion structural capacity tions ity mechani- hazard hazard decline zation hazard (i) (m) (n) (r) (y) (D (k) (q) (w) (e) (s)

Bellevue series Poorly drained Poor to Low to fair moderate

Gilgai complex Poorly drained Fair Moder- Nil to Moderate Moderate Moder- ate to very low ately low high

Andrew series Poorly drained Poor to Moder- fair ate to high

Cruse series Moderately Moderate Low to Good Low to Nil to Moderate Very high High Very low Moderate well to imper- moderate high very low to high fectly drained Drainage line com- Poorly drained High Low to plex moderate

Solonchak Saline to (unnamed) highly saline

Claypans Poorly drained Fair to poor

(0) Alluvial soils

Swan sand Moderately Moder- Moderate Excellent Nil to Nil to High Very high Moderate Very low Low to well to well ately high very low very low moderate drained

Swan sandy Moderately Moder- Moderate Excellent Nil to Nil to High Very high Moder- Very low Moderate loam/clay loam well to well ately high to very very low very low ately low drained good to moder- ate

Belhus sand Well drained Moder- Moderate Excellent Nil to Nil to High Very high Moderate Very low Low ately high very low very low to high

Houghton series Well drained Moderate Low to Excellent Nil to Nil to High Very high High Very low Low moderate very low very low

Pyrton series Moderately Moder- Moderate Excellent Nil to Moder- Low Very high Moder- Very low \1oderate well to well ately high to high very low ate to ately low drained high

Pyrton sand Well drained Moder- Low Excellent Nil to High Moderate Very high Moder- Very low Low ately low very low to high ately low to moder- to moder- ate ate

LAND RESDURCES SERIES No.6 40 Table 2. continlled

Map Unit Site Moisture Nutrient Rooting Salinity Flood Soil Potential Wind Water Soil drainage holding retention can d i - hazard hazard workabil- for erosion erosion structural capacity tions ity mechani- hazard hazard decline zation hazard (i) (m) (n) (r) (y) (n (k ) (q) (w) (e) (5)

(E) Aeolian and miscellaneous soils Karrakatta sand Well to rapidly Low Very low Excellent Nil to Nil to High Very high Very high Very low Lo\v drained very low very low

Karrakatta sand Rapidly Very low Very low- Excellent Nil to Nil to High Very high Ve ry high Very low Low (grey phase) drained tala\\' extremely very low very low low

Muchea sand Rapidly Very low Ex- Very Moder- Nil to High Very high Very high Very low Low drained to low tremely good ate very low low

Barrett sand Poorly dmined Low Very low- Good High Nil to High Very high Very high Very low Low extremely very low low

Bibra sand Poorly drained Low Very low- Good High Nil to Moderate Very high Very high Very low Low extremely very low to high low

Env. Geology 1 : 50 000 Series, Muchea Sheet. 510 Rapidly Very low Ex- Excellent Nil to Nil to High Very high Very high Very low Low drained tremely very low very low low

S12 (Yellow sand) Well to rapidly Moder- Very low Excellent Nil to Nil to High Very high Very high Very low Low drained ately low very low very low to 1m"

Msgl Moderately Moderate Low Good to Nil to Nil to High Very high Moderate Very low Low well drained very very low very low good

41 LAND RESO URCES SERIES No.6 Land quality descriptions and values Appendix 3.

The following descri]?tions of each land quality are derived from Moore 3.1 Site drainage (i) (1990). The tables descnbe the values for each land quality. The number of The land quality, site drainage values for each land quality varies from three to six. The lower numbered values generally being more favourable for plant growth. (waterlogging), refers to the overall site and internal soil drainage. Drainage is influenced by internal factors including soil texture, struc­ Appendix Land quality (symbol) ture, water-holding capacity, the Table presence of an impermeable layer, the depth to this layer if present A3.1 Site drainage 0) and external factors including the A3.2 Moisture holding capacity (m) slope and the amount of run-on. A3.3 Nutrient availability (n) A3.4 Rooting conditions Cr) For irrigated horticulture, a weJl A3.5 Salinity hazard (y) A3.6 Rood hazard m drained site is a major priority. A3.7 Potential for mechanization (q) Soils which are naturally well A3.8 Soil workability (k) drained have an added advantage A3.9 Wind erosion hazard (w) A3.10 Water erosion hazard (e) for horticulture with a low prolifer­ A3.11 Soil structural decline hazard (5) ation of root diseases and soil borne pathogens. If the drainage in an area is a limiting factor then surface and sub-surface drains may be installed. The feasibility of in­ Table A3.I. Site drainage (i) stalling drains to alleviate a water­ logging problem is determined by Numerical the soil type and whether there is Value rating Description anywhere to drain the water. The capability ratings assume no addi­ Very poorly drained 6 Water is removed from the soil so slowly tional drainage has been installed. that the water table remains at or near the surface for most of the year. The feasibility of installing drains Poorly drained 5 Water is removed very slowly in relation was not included, because it is not to supply. All horizons remain water­ an inherent characteristic of the logged for periods of several months. map unit. Consequently an area Imperfectly drained 4 Water is removed only slowly in relation which has a marginal capability to supply. Some horizons may be mottled due to a waterlogging constraint and / or have orange or rusty linings of root channels, and are waterlogged for mayor may not be readily drained. periods of several weeks. Moderately well 3 Water is removed from the soil somewhat drained slowly in relation to supply, because of low permeability, shallow water table, lack of gradient, or some combination of these. Some horizons may remain water­ logged for as long as one week after addition of water. Well drained 2 Water is removed from the soil readily, but not rapidly. Some horizons may re­ main waterlogged for several days after addition of water. Rapidly drained Water is removed from the soil rapidly in relation to supply. No horizon is normally waterlogged/wet for more than several hours after addition of \,vater.

LAND RESOURCES SER IES No.6 42 Table A3.2. Moisture holding capacity (m) 3.2 Moisture holding capacity (m)

Numerical The land quality, moisture hold­ Value rating Description ing capacity, is closely related to the available water capacity (AWe). The AWe is the amount of Very low 6 Moderately deep to deep soils with a very IO\\' available water capacity" (AWe) of water held in the soil between field capacity and permanent wilting < 20 mm H20 / m. Alternatively, soils in which the moisture availability is re~ point. The moisture holding capac­ stricted by the shallow effective rooting ity is mainly a function of the soil depth. Soil types include coarse, uniform sands (e.g. Bassendean series) and skeletal texture and the effective soil depth soils. (Appendix 3.4). On some soil types Low 5 Moderately deep to deep soils with a low deep-rooted plants have an advan­ tage over shallow-rooted plants AWe of 20-50 mm H20 /m. In addition, soils with restricted moisture availability and are able to extract more water because of moderately shallow rooting from the profile. Moisture holding conditions. Soil types include uniform capacity is only a significant limita­ sands with an earthy fabric, or minor clay content (e.g. Kilrrakatta sand (yellow tion for most horticultural crops phase» and shallow, sandy duplex soils. when the AWe is extremely low. Moderately low 4 Moderately deep to deep soils with an Otherwise, differences in the AWe AWe of 50-80 mm H,O / m. Also moder­ only affect the frequency of irriga­ ately shallow soils \\'ith a moderate Awe tion scheduling. On soils with an Soil types include uniform fine sands and extremely low Awe crops may moderately deep, sandy duplex soils. suffer moisture stress under high Moderate 3 Moderately deep to deep soils with an evaporative demand conditions AWe of about 120 mm H20/m. Soil types include uniform si1lldy loams and duplex even if the crop is irrigated two or soils with medium textured A horizons three times a day. These soils also (e.g. Herne sandy loam). have higher irrigation require­ Moderately high 2 Moderately deep to deep soils with an ments.

AWe of about 160 mm H20 / m. Soil types include duplex soils with medium tex­ tured topsoils overlying well structured or earthy B horizons (e.g. Swan sandy loam). High Deep to very deep soils \vith an AWe

probably> 160 mm H20 / m. Soil types include deep, uniform loams (e.g. Pyrton loam) and deep, gradational soils.

, Available water capacity (AWC) is the difference between the amount of water held at field capacity and the amount held at permanent wilting point.

43 LAND RESOURCES SERIES No.6 Table A3.3. Nutrient availability (n) 3.3 Nutrient availability (n) The nutrient availability of soils Numerical Value rating Description depends upon soil characteristics including soil texture, cation ex­ change capacity, the organic matter Extremely low 5 Soils are inherently of low fertility and content and the pH. Soils with a may have gross deficiencies of the major elements. The cation exchange capacity low exchange capacity ,...,hich are (C EC) in the surface 20 cm is probably < 3 readily leached and soils with high meq/ 1oa g, and applied nutrients are fixing capacities are naturally low readily leached down the profile. Soil in available nutrients. types are highly leached, pale or bleached deep sands (e.g. Gavin series of the Bas­ For intensive horticulture (i .e. sendean Sand). market gardening), the copious Very low 4 Soils with a very low nutrient availability. amounts of fertilizer applied and These soils '·"ould have an inherently low natural fertility and there would be some the relatively low cost of fertilizer leaching of applied nutrients. The CEC compared with other production would normally be in the range 3-6 costs negates the need to use natu­ meg/100 g. Soil types include deeper rally fertile soils. The relative im­ sandy duplex soi ls where the clay subsoil portance of nutrient availability is > 30 cm and deep sands with high organic matter content (e.g. Joel series of increases with the generally less the Bassendean sands) and some soils of intensive perennial crops (i.e. viti­ the Spearwood and Quindalup series. culture, stone fruit). Low 3 Soils with a low natural fertility and regular fertilizer applications are neces­ sary. There would be some leaching of applied nutrients out of the topsoil and/ or fixing may take place. The CEC is proba­ bly in the range 6-12 meq/lOO g. Soil types include duplex soils with bleached A2 horizons and Spearwood and Quindalup series. Moderate 2 Soils are naturally more fertile, although regular fertilizer applications would be necessary if the soils are used for annual crops. The CEC would be in the range 12-20 meq/lOO g and there would not be any extremes of pH or Fep) content. Soil types include red, yellow and brown duplex soils and gradational earths. High Soils are highly fertile and only infrequent applications of fertilizer would be neces­ sary. The CEC is > 20 meq/lOO g, the pH is neutral and there is only a low Fe20 3 content. Soil types in this category are rare in Australia. The only soils to fit this class wi thin the study are certain recent alluvial soils (e.g. Pyrton loam).

LAND RESOURCES SERIES No.6 44 Table A3.4. Rooting conditions (r) 3.4 Rooting conditions (r)

Numerical Rooting conditions refers specifi­ Value rating Description ca lly to root room and mechanical impedance. Root room is the soil volume available for root growth 5 Shallow soils with an effective soil depth < 0.2 m. Alternatively the soils are moder­ and is predominantly a function of ately shallow (0.2-0.5 m) with a high the effective soil depth, porosity (> 50%) gravel/stone content. Soil types and pore size distribution and con­ include skeletal soi ls over bedrock and tent of coarse fragments. Gravels some very poorly drained soils. and stone in the soil profile reduce Fair 4 Moderately shallow soils with an effective the soil volume in proportion to soil depth from 0.2-0.5 m. Alternatively the their abundance. The effective soil soils are moderately deep (0.5-1.0 m) with a high (> 50%) gravel stone content. Soil depth is the depth to an impenetra­ types include duplex soils with a massive, ble barrier such as rock, a cemented impemleable B horizon. ironstone pan or a dense, massive Good 3 Moderately deep soils with an effective clay subsoil. A perched or penna­ soil depth from 0.5-1.0 m. Alternatively the nent water table can also act as a soils are deep (> 1.0 m) with a high (> 50%) barrier to root development. For gravel/stone content. Soil types include gravelly duplex soi ls tlnd duplex soils with this study an impenetrable layer is well structured subsoils. deemed to be any la yer which Very good 2 Deep soils with an effective soil depth impedes the development of the between 1-2 m. Soil types include the majority of the roots. transitional soils between the deep, sandy duplex soils and the uniform sands. Excellent Very deep soils wi th an effective soil depth > 2 m. Soil types include uniform sands and gradational earths.

45 LAND RESOURCES SERIES No.6 Table A3.S. Sali n ity hazard (y) 3.5 Salinity hazard (y) Salinity is caused by high 'i-vater Numerical Value Descri pt~on rating tables with the capillary rise of groundwater into the root zone and the subsequent concentration Highly saline 5 Areas which are presently highly saline, of salt at or close to the surface with a surface (0-0.2 m) soil salinity level through evapotranspiration. Exist­ greater than 1200 ).lS/cm. Ground cover is likely to be absent or a sparse cover of ing salinity can be detected highly salt tolerant species. There is likely through a soil test or inferred from to be a saline water table within one metre the vegetation type, while in severe of the surface. cases white crystalline salt may be Saline 4 Areas ..vhich are presently saline, with a visible on the soil surface. Any land surface (0-0.2 m) soil salinity level 600- which already shows symptoms of 1200 !lSI cm. Pastures would be domi­ nated by sea barley grass (HordeulII l1Ior­ salinity should not be considered illllln) with an absence of clovers. The for horticulture. In areas which are water table is likely to be within 2 m of the presently non-saline, the salinity surface. hazard under irrigation is difficult (High salinity hazard) 3 Areas which are presently non-saline, to determine. It can be related to Non-saline although there is a high risk of salinity the level of any existing water developing if they are irrigated. The surface (0-0.2 m) soil salinity level is tables, the permeability of the soil < 600 ~S/cm, although the water table and the salt storage in the soil may be within 1 to 2 metres of the surface. profile. The Bibra sand of the Bas­ (Modera te salinity 2 Areas which are presently non-saline} sendean association is subject to hazard) although there is a moderate risk of high water tables during the winter Non-saline salinity developing if they are irrigated. months, although the likelihood of The water table may be about 2 m below salinity developing is low. This is the surface. because of the highly permeable (Nil to low salinity Areas which are presently non-saline and nature of the soil and the very low hazard) the likelihood of salinity developing, if Non-saline irrigated, is slight. levels of salt stored in the profile.

LAND RESOURCES SERIES No.6 46 Table A3.6. Flood hazard (f) 3.6 Flood hazard (f) Flooding is a temporary condi­ Numerical Value rating Descri ption tion because of excessive run-off following heavy rainfall events and usually involves moving water. It High 4 Frequent, physically damaging or pro­ may be differentiated from water­ longed floods. The flood return period is less than one year. logging, which can include ponded water because of high water tables. Moderate 3 Fairly frequent, physically damaging or prolonged floods. The flood return period Flooding may also involve physical is one year to ten years. damage, with crops being flattened Low 2 Infrequent, physically damaging or pro­ and erosion damage through the longed floods. The flood return period is removal of topsoil. Horticultural ten years to 100 years. crops vary in their tolerance to Nil to very low Negligible flood hazard; either not subject flooding, while the timing of any to flooding or the flood return period is flood is also critical. Grapevines are > 100 years. fairly tolerant of flooding during their dormant phase over winter, although considerably less tolerant during spring. Many perennial crops have a productive lifespan of 10-30 years, therefore even infre­ quent floods (]:1O years or less frequent) are likely to occur within the lifespan of the crop.

Table A3.7. Potential for mechanization (q)

Numerical Value rating Description

Nil 5 Either excessive slopes (> 25%), or the abundance of rock outcrop (> 15%) pro­ hibit mechanization. 4 Low potential for mechanization because of moderately steep slopes (15-25 '1'0) , the abundance of rock outcrop (10-15%), or a combination of the two. Alternatively, on flat to gently ,loping land, den,e gilgai microrelief can severely restrict mechani­ zation. Moderate 3 Moderate potential for mechanization be­ 3.7 Potential for mechanization (q) cause of slope 00-15%), the abundance of The land quality potential for rock outcrop 0-10%), or a combination of mechanization refers to land fea­ the two. On flat to gently sloping land, dense shallow gilgai microrelief can re­ tures which directly help or hinder strict mechanization. mechanized agricultural opera­ High 2 Slight restriction to mechanization because tions. Hindrances include surface of slope (5-10%), or scattered gilgai mi­ rocks, rock outcrop, gilgai microre­ crorelief. lief and excessive slope. This land Very high Flat to gently sloping land (0-5%), rock quality is distinct from 'soil work­ outcrop and gilgai microrelief are absent. ability' which refers to the ease of cultivation.

47 LAND RESOURCES SERIES No.6 Table A3.B. Soil workability (k) 3.8 Soil workability (k)

Numerical Soil workability is the ease with Value rating Descri ption which a soil can be tilled. The workability of a soil depends on a number of interrelated soil charac­ Low 3 Soil factors greatly restrict cultivation and teristics including texture, struc­ these soils can only be cultivated satisfac­ torily over a narrow moisture range. When ture, organic matter content, hard­ dry, the soil is too hard to work and tends setting nature and the amount of to get excessively boggy for long periods gravel or stone in the surface layer. in winter. These soils may be poorly or very poorly drained and/or the heavy textured surface soils are massive and hard-setting. Moderate 2 Soil factors restrict cultivation in most years to some ex tent and there will be periods in winter when the soil is boggy. Surface soils are usually medium textured with a firm surface soil condition. Site drainage is poorly drained to moderately well drained.

High Under normal conditions soil factors rarely restrict cultivation. The soil can be worked over a wide moisture range and can normally be worked within 72 hour~ of significant rainfall. Surface seils are usually light textured (Texture groups 1 and 2) with a single grain structure, or massive with a soft surface soil condition. Soils would normally be moderately well drained to rapidly drained.

LA D RESOURCES SERIES NO.6 4lI Table A3.9. Wind erosion hazard (w) 3.9 Wind erosion hazard (w)

Numerical Wind erosion hazard refers to Value Description rating the ease with which soil particles are detached and transported from land surfaces by the action of the Very high 5 Highly erodible soils in moderate to highly exposed positions: wind. Transport of wind-blown particles can occur through salta­ The soils are uniform sands with a single grain structure and a loose surface condi­ tion, suspension or surface creep tion. The sand fraction is medium to fine. (Bagnold 1941). Wind erosion haz­ Soil types include dune sands and deep ard is a combination of climatic, sands on a plain (e.g. Gavin sand and landform and soil factors. Climatic Karrakatta sand). factors include the frequency, High 4 Moderately to highly erodible soils: strength and direction of erosive Surface soils have a single grain structure winds (wind speed > 30 km/ h). and may be loose with a coarse sand Landform, including aspect, is a fraction, or have a surface crust and a predominantly fin e sa nd fraction. Surface major determinant of exposure. soil textures are generally light; sands to Soil factors include the surface loamy sands. Soil types include uniform condition, surface structure and deep sa nds and duplex soils (e.g. texture, particularly the fine sand Houghton sand, Herne series). component. Soil types with a moderate erodibility: Moderate 3 In general, wind erosion is not a There is a wide range of soils in this major problem for horticultural category including light textured soils (sands to loamy sands) with a massive to land uses. Annual crops tend to be weakly pedal surface structure and a soft more susceptible than perennial to firm surface condition when dry. Also, crops. For annual crops, the wind sandy soils with a significant surface erosion hazard is highest during gravel component and self-mulching clays with a loose surface condition and with an the preparation of the soil before average ped size < 1 mm. Examples in­ planting and at the seedling stage clude, lotons series, and Pyrton sand. when the canopy cover is low. Moderately low 2 Soils with a moderately low erodibility: Significant production losses can Soil types include medium to heavy tex­ occur through crop sand-blasting. tured soils, except for those with a hard­ Control is through windbreaks and setting surface condition. Also, hard­ the application of additional irriga­ setting light textured soils. Examples in­ tion to maintain the moisture con­ clude, Pyrton series. tent of the surface soil. With the Low Soils with a low erodibility: development of improved irriga­ Soil types include hard-setting medium to tion systems to reduce watering heavy textured soils. Also, all soil types rates, windbreaks may be the pre­ which are very poorly drained (i.e. the ferred option. surface remains moist to wet for the whole year). Examples include, swamp soils and Bellevue series.

49 LAND RESOURCES SERIES NO.6 Table A3.10. Water erosion ha zard (e) 3.10 Water erosion hazard (e) Water erosion is a process in Numerical Value Description rating which soil is detached and trans­ ported from the land by the action of rainfall, run-off and seepage. Very high 5 Highly erodible· soils on slopes of 20-30%, Common types of water erosion together with any slopes> 30%. include sheet, rill, gully, stream High 4 Highly erodible soils on slopes of 10-20%, bank and tunnel erosion or moderately erodible soils on slopes of 20-30%. (Houghton and Charman 1986). In the Swan Valley, water erosion is Moderate 3 Highly erodible soils on slopes of 3-10%, or moderately erodible soils on slopes of generally not a major constraint 10-20%, or soils of low erodibility on because of the low relief and high slopes of 20-30%. infiltration rates on the sandy soils. Low 2 Highly erodible soils on slopes < 3%, or A simple classifica tion based pre­ moderately erodible soils on slopes of dominantly on slope has been used 3-10%, or soils of low erodibility on slopes to assess the water erosion hazard. of 3-20%. Very low Low to moderately erodible soils on slopes <3% .

• Soil erodibility: Is a function of the soil resistance to detachment and the rainfall acceptance rate in winter.

Table A3.n. Soil structural decline hazard (s) 3.11 Soil structural decline hazard (s) Numerical Value Descri ption This land quality refers to the rating decline in the soil structure com­ pared with the pristine state. It High 3 Soil structure adversely affected under could take the form of surface continued cultivation, resulting in sub­ slaking, development of a hard­ stantial yield penalties. This situation is not easily reversed. setting surface, decrease in pedality or the development of a traffic Moderate 2 Soil structure adversely affected under continued cultivation. This situation can hardpan. In the Swan Valley, traffic be economically reversed. For example, hardpans induced by machinery the development of a traffic or cultivation movement between the vine rows hardpan on duplex soils with light tex­ are quite common. The increase in tured A horizons. the bulk density 01 the soil and Nil-low Soil structure suffers nil to minor degrada­ decrease in permeability, especially tion under continued cultivation. Any yield lossses are small and would not under the wheel tracks, can exacer­ offset costs of treatment. Surface soils are bate any waterlogging problems usually single grained or highly pedal (Smith et al. 1969). (self-mulching).

LAND RESOURCES SERIES No.6 50 Land capability rating tables for each land use type Appendix 4.

The following tables are to be read in conjunction with the land quality descriptions and values in the tables in Appendix 3.

Table A4.1. Land capability rating for table g rapes

Capability class Land quality" II lIT IV V

Site drainage (i) Rapidly drained (1) Moderately well Imperfectly Poorly drained (5) Well drained (2) drained (3) drained (4) Very poorly drained (6)

Moisture holding capacity (m) High (]) Moderately low Low eS) Very low (6) Moderately high (4) (2) Moderate (3)

Nutrient availability (n) High 0), Moder- Very low (4) Extremely low (5) ate (2), Low (3)

Rooting conditions (r) Excellent (1) Very good (2) Good (3) Fair (4) Poor (5)

Salinity hazard (y) Nil-low 0), Highly saline (5) Moderate (2) Saline (4)

Flood hazard (f) Very low-nil (1) Low (2) Moderate (3), High (4)

Potential for mechanization (q) Very high (I), Moderate (3) Low (4) Nil (5) High (2)

Soi! workability (k) High (1) Moderate (2) Low (3)

Wind erosion hazard (w) Low 0), Moder- High (4) Very high (5) ately low (2). Moderate (3)

Water erosion hazard (e) Very low (1), Moderate (3) High (4) Very high (5) Low (2)

Soil structural decline hazard (5) Low (1) Moderate (2) High (3)

... See descriptive tables for land qualities in Appendix 3. Note: The numerals in parentheses correspond to the numerical ratings as given for each land quality in the corresponding tables in Appendix 3.

51 LAND RESOURCES SERIES No.6 Table A4.2. land capability rating for wine grapes

Capability class Land quality" II III IV V

Site drainage (j) Rapidly drained 0 ) Im perfectly Poorly drained (5) Well drained (2) drained (4) Very poorly Moderately well drained (6) drained (3)

Moisture holding capacity (m) High (1), Moder- Moderately low Low(S) Very 1m." (6) ately high (2), (4) Moderate (3)

Nutrient availability (n) Low (3) Moderate (2), H;gh 0), Very low (4) Extremely low (5)

Rooting conditions (r) Excellent (1), Good (3) Fair (4) Poor (5) Very good (2)

Salinity ha za rd (y) Nil-low 0), Highly saline (5) Moderate (2) Saline (4)

Flood hazard (f) Nil-very low 0) Low (2) Moderate (3) H;gh (4)

Potential for mechanization (q) Very high (1), Moderate (3) Low (4) Nil (5) High (2)

Soil workability (k) High (1) Moderate (2) Low (3)

Wind erosion hazard (w) Low (1), Moder- High (4) Very high (5) ately low (2), Moderate (3)

Water erosion hazard (e) Very low (1), Moderate (3) H;gh (4) Very h;gh (5) Low (2)

Soil structural decline hazard (s) Low (]) Moderate (2) High (3)

* See descriptive tables for land qualities in Appendix 3. Note: The numerals in parentheses correspond to the numerical ratings as given for each land quality in the corresponding tables in Appendix 3.

LAl\lO RESOURCES SERIES No.6 52 Table A4.3. Land capability rating table for dried vine fruit

Capability class Land quality" II III IV V

Site drainage (i) Rapidly drained (1) Imperfectly Poorly drained (5) Well drained (2) drained (4) Very poorly Moderately well drained (6) drained (3)

Moisture holding capacity (m) High (1), Moderate (3) Moderately low Low (5) Very [ow (6) Moderately high (4) (2)

Nutrient availability (n) Low (3) Moderate (2) High (1). Very low Extremely low (5) (4)

Rooting conditions (d Excellent (1) Good (3) Fair (4) Poce (5) Very good (2)

Salinity hazard (y) Nil-low (I), Highly saline (5) Moderate (2) Saline (4)

Flood hazard (f) Ni1-very low Ot Moderate (3) High (4) Low (2)

Potential for mechanization (q) Very high (1), Moderate (3) Low (4) Nil (5) High (2)

Soil workability (k) High (1) Moderate (2) Low (3)

Wind erosion hazard (w) Low (1), Moder- High (4) Very high (5) ately low (2), Moderate (3)

Water erosion hazard (e) Very low (I), Moderate (3) High (4) Very high (5) Low (2)

Soil structural decline hazard (s) Low (I) Moderate (2) High (3)

.. See descriptive tables fo r land qualities in Appendix 3. Note: The numerals in parentheses correspond to the numerical ratings as given for each land quality in the corresponding tables in Appendix 3.

53 LAND RESOURCES SERIES No.6 Table A4.4. Land capability ra ting table for citrus

Capability class Land quality· II III IV V

Site drainage (i) Rapidly drained (1) Moderately well Imperfectly Well drained (2) drained (3) drained (4) Poorly drained (5) Very poorly drained (6)

Moisture holding capacity (m) High (1), Moder- Moderately Very low (6) ately high (2), low (4), Low (5) Moderate (3)

Nutrient availability (n) High (1), Low (3), Extremely low (5) Moderate (2) Very low (4)

Rooting conditions (r) Excellent (1), Very Good (3) Fair (4), Poor (5) good (2)

Salinity hazard (g) Nil-low 0) Moderate (2) Highly saline (5) Saline (4)

Flood hazard (f) Nil-very low 0), Moderate (3), Low (2) High (4)

Potential for mechanization (q) Very high (l), Moderate (3) Low (4) Nil (5) High (2)

Soil workability (k) High (1) Moderate (2) Low (3)

Wind erosion hazard (w) Low 0), Moder- Very high (5) alely low (2), Moderale (3), High (4)

Water erosion hazard (e) Very low (1), Moderale (3) High (4) Very high (5) Low (2)

Soil structural decline hazard (5) Low (]), High (3) Moderale (2)

"" See descriptive tables for land qualities in Appendix 3. Note: The numerals in parentheses correspond to the numerical ratings as given for each land qua lity in the corresponding tables in Appendix 3.

LAND RESOURCES SERIES No.6 54 Table A4.S. Land capability rating table for stone fruit

Capability class Land quality" II III IV V

Site drainage (i) Rapidly drained (1) Moderately well Imperfectly Poorly drained (5) Well drained (2) drained (3) drained (4) Very poorly drained (6)

Moisture holding capClcity (m) High (1), Moder: Moderately Very low (6) ately high (2)' low (4), Low (5) Moderate (3)

Nutrient availability (n) High (1), Moder­ Very 100v (4) Extremely low (5) ate (2), Low (3)

Rooting conditions (r) Excellent 0), Very Good (3) Fair (4) Poor (5) good (2)

Salinity hazard (y) Nil-low (1) Moderate (2) Highly saline (5) Saline (4)

Flood hazard (f) Nil-very low (t) Low (2) Moderate (3) High (4)

Potential for mechanization (q) Very high (1), Moderate (3) Low (4) Nil (5) High (2)

Soil workability (k) High (1) Moderate (2) Low (3)

Wind erosion hazard (w) Low (1), Moder­ Very high (5) ately low (2), Moderate (3), High (4)

Water erosion hazard (e) Very low (1), Moderate (3) High (4) Very high (5) Low (2)

Soil structural decline hazard (s) Low (1), High (3) Moderate (2)

.. See descriptive tables for land qualities in Appendix 3. Note: The numerals in parentheses correspond to the numerical ratings as given for each land quality in the corresponding tables in Appendix 3.

55 LAND RESOURCES SERIES No.6 Table A4. 6. Land capabili ty rating tab le for market gardening

Capability class Land quality'" II III IV V

Site drainage 0) Rapidly drained 0) Moderately well Imperfectly Poorly drained (5) Well drained (2) drained (3) drained (4) Very poorly drained (6)

Moisture holding capacity (m) High 0), Moder· Very low (6) ately high (2), Moderate (3), Moderately low (4), Low (5)

Nutrient availability (n) High (j), Mod.,- Extremely Imv (5) ate (2), Low (3), Very low (4)

Rooting conditions (r) Excellent (1), Very Good (3) Fair (4) Poor (5) good (2)

Salinity hazard (y) Nil·low (1) Moderate (2) Highly saline (5) Saline (4)

Flood haza rd (f) Nil-very low (1) Low (2) Moderate (3), High (-I)

Potential for mechanization (q) Very high (1) High (2) Moderate (3) Low (4) Nil (5)

Soil workability (k) High (1) Moderate (2) Low (3)

Wind erosion hazard (w) Low (1), Moder- ately low (2), Moderate (3), High (4), Very high (5)

Water erosion haza rd (e) Very low (1) Low (2) Moderate (3) High (4) Very high (5)

Soil structural decline hazard (s) Low (1) Moderate (2) High (3)

• See descripti ve tables for land qualities in Appendix 3. Note: The numera ls in parentheses correspond to the numerical rati ngs as given fo r each land quality in the corresponding tables in Appendix 3.

LAN D RESOU RCES SERIES No. 6 56 Maps available on the GIS Appendix 5. The maps for this project were produced on a computer graphics system by the Geographic Informa­ tion Systems (GIS) group of the Department of Agriculture. The inlormation available on the sys­ tem is outlined below. Different sets of information can be overlaid or viewed separately on either a graphics terminal or on a hard copy plot (colour or black / white).

• Locality names, roads, road names, rivers and tributaries, ca­ dastre • Soil map (from Pym 1955) • Land capability interpretive maps lor; Table grapes Wine grapes Dried vine Iruit Stone fruit Citrus Market gardening • Phosphate retention ability(l) Nitrate retention ability(l)

(I) from Moore (1990).

Note: These maps can be obtained through The Commercial Land Resource Information Group Department of Agriculture, Western Australia Baron-Hay Court South Perth, WA, 6151 Tel: (09) 368 3333 Fax: (09) 368 3355

57 LAND RESOURCES SERIES No.6 Groundwater resources of the Swan Valley Appendix 6. The fresh groundwater resources western part of the Swan Ground­ of the Swan Valley are in three water Area, gradually thinning to main aquifer systems; the uncon­ the east until it pinches out east of fined superficial formation and the the Swan River. It consists of varia­ confined Osborne and Leederville ble beds of shale and clayey sands formations. The three formations with some sandy facies. are multi-layered aquifers contain­ ing strata controlled flow systems Groundwater in the Osborne for­ which may be discrete or in lateral mation originates as downward or vertical hydraulic connection seepage from the superficial forma­ with adjacent aquifers. The follow­ tions, principally in the area of the ing descriptions of each aquifer Gnangara mound. From the Gnan­ have been taken from Steen (1984) gara mound water discharges and Allen (1980). downward to the Leederville for­ mation, while in the vicinity of the Swan River it discharges upwards Superficial formations to the superficial formation. The shallow, unconfined superfi­ cial formations overlie both the Osborne and Leederville forma­ tions. They are of variable thick­ Leederville formation ness and consist largely of sand The main aquifers of the Swan and clay. The clay content increases Valley are in the sandstone beds of in an easterly direction with a the Leederville formation. The for­ corresponding decrease in ground­ mation is about 300 m thick and water storage. dips westward from its eastern Water from the Gnangara limit at the Darling Scarp. The Mound is discharged, horizontally, formation consists of alternating east through the formation to the layers of sandstone and shale and Swan River and into tributaries and is underlain by the South Perth also downwards through the shale, which effectively stops Osborne formation to the Leeder­ downward movement. ville formation. Along the base of the valley the Osborne and Leeder­ The major flow system of the ville formations discharge verti­ area is the western system of the cally upwards into the superficial Leederville formation. Recharge oc­ formations. This groundwater is curs to the west of the Swan Valley removed by either evapotranspira­ where there is downward seepage tion or drainage into the Swan from the Gnangara mound, River. In the eastern part of the through sandy facies in the Swan Valley, groundwater in the Osborne formation to the Leeder­ superficial formation flows west­ ville formation. Groundwater ward towards the Swan River. flows eastward from this area to discharge into the overlying super­ Water quality in the superficial ficial formations. formations deteriorates in areas close to the Swan River, or along Water quality within the Leeder­ the streams that feed into the Swan ville formation deteriorates with River from the east, such as Jane depth. The upper half generally and Susannah Brooks. contains potable water, while the lower half contains water with salinities ranging from 1000 mg/L Osborne formation to 4000 mg/L TSS*. However, in The Osborne formation overlies the area of discharge the quality of most of the western flow system of groundwater in the upper Leeder­ the Leederville formation. The for­ ville formation deteriorates east of mation is about 160 m thick in the the Swan River.

* TSS = Total soluble solids.

LAND RESOURCES SERIES No.6 58 Maps Appendix 7. (2 sheets)

Soils (Pym, 1955) plus roads and cadastral information (1:25,000). Land capability interpretative map for table grape production (1 :50,000).

59 LAND RESOURCES SERIES No.6 00663f2191-500-U5362 GARRY L DUFFIELD, Government Printer, Western Australia