>'.r->® am
i fc > MIJN !^i jv;. Mini stry of Açf:ir-icîTJ.IL
National ic2u.IL
Fertilizer Use
(Phase X)
Annex XXX
Description of tln^ First Priority
Sites in trie Various Districts
23
Kir Di strict
District No.: 2 3
Nairobi, June 1987 IL JL z «3xr Use o. on.
C 3F»liai s o X
Team of Consultants1) Professional Staff from NAL2)
Project Coordination H. Strobel (ed.) G.Hinga Project Coordinator Director NAL
S.W.Nandwa Counterpart Coordinator
Aaro—Climatoloaists R. Jätzold J.W. Onyango R. Rotter
Soil Scientists / Surveyors R.F. van de Weg F.N. Muchena E.M.A. Smaling C.K.K. Gachene J.M. Kibe
Soil Chemists P. Pietrowicz J.N. Qureshi P.O.S. Oduor
Aaronomi sts A.Y. Allan J.O. Owuor
Data Processing H. Mayr R.L. Milikau R. Dölger D.K. Wamae A. Muliro
Land Surveyors R. Rotter B. Mwangi S. Wataka
Animal Production W. Bayer
1) German Agency for Technical Cooperation (GTZ) (German Agricultural Team (GAT))
2) National Agricultural Laboratories Corv i-t-i£=; o-P tbe Fi
zu : Methodology and Inventory of Existing Information
Ann. ezx X Compilation. of results from Former Fertilizer Trials In Kenya (2 Volumes)
À.n.ri &ZX. X X - X Inventory of Farming Systems Research in Kenya
Ann X - 2. Influence of Fertilizer Application on Ruminant Production
Maintaining Soil Fertility with Little or No Use of Fertilizers
XXX Detailed Description of the First Priority Sites in the Various Districts :
1. Kisii 17. Narok 2. South Nyanza 18. Samburu 3. Kisumu 19. Nyandarua 4. Siaya 20. Kiambu 5. Busia 21. Muranga 6. Bungoma 22. Nyeri 7. Kakamega 23. Kirinyaga 8. Nandi 24. Embu 9. Kericho 25. Meru 10. Trans Nzoia 26. Machakos 11. Uasin Gishu 27. Kitui 12. West Pokot 28. Lamu 13. Keyo Marakwet 29. Kilifi 14. Baringo 30. Taita Taveta 15. Laikipia 31. Kwale 16. Nakuru 32. Nairobi
Annex XV : Description of Computer Programmes Established in Phase I
Scanned from original by ISRIC - World Soil Information, as ICSU World Data Centre for Soils. The purpose is to make a safe depository for endangered documents and to make the accrued information available for consultation, following Fair Use Guidelines. Every effort is taken to respect Copyright of the materials within the archives where the identification of the Copyright holder is clear and, where feasible, to contact the originators. For questions please contact soil.isrictawur.nl indicating the item reference number concerned. District: Kirinyaga General Aspects 23.0
Annex III. Volume 23
Page
Chapter 23-Or
General Aspects 0.1
Legend of the Soil Map of Kirinyaga District 0.25
Chapter 2 3-3- =
Description of the Kerugoya Trial Site 1.1
Please note the following numbering mode of Tables and Maps: First Number District Number Second Number Trial Site Number Third Number Number of Table or Map within Chapter.
- 0.1 - District : Kirinyaga General Aspects 23.0
Contents of Chapter 23.0:
'General Aspects
Page
1. Climate and Soils of the District 0.3
2. Location of the Trial Site and Criteria for its Final Position 0.10 3. Names and Addresses of Government Officers Involved in FURP Activities 0.13
4. Trial Design and Execution Plan 0.14
5. Areas in Kirinyaga District Represented by FURP Trial Sites 0.14
List of Tables
Table 23.0.1 Climate in the Agro-Ecological Zones of Kirinyaga District 0.6
Table 23.0.2 Agro-Ecological Zone and Soil Classification of the
Trial Site 0.9
Table 23.0.3 Ratings of Criteria Used for Trial Site Selection 0.10
Table 23.0.4 Names and Addresses of Government Officers in the District 0.13 Table 23.0.5 Major Soil Properties and Climatic Conditions of the Agro-Ecological Units in Kirinyaga District 0.21
List of Maps
Map 23.0.1 66% Reliability of Rainfall in First Rains 0.4
Map 23.0.2 66% Reliability of Rainfall in Second Rains 0.5
Map 23.0.3 Agro-Ecological Zones and the Trial Sites in the District 0.7
Map 23.0.4 Soils and Trial Sites in Kirinyaga District 0.11
Map 23.0.5 Groupings of Soil Mapping Units Represented by the
Trial Site in Kirinyaga District 0.19
Map 23.0.6 Agro-Ecological Units in Kirinyaga District 0.23
Legend of the Soil Map of Kirinyaga District 0.25
- 0.2 - District: Kirinyaga General Aspects 23.0
1. Climate and Soils of the District
The typical agro-ecological pattern of the south-eastern slopes of the Nyandarua Range is continued on the southern and eastern slopes of Mount Kenya due to the effects of the south-east Trade Winds increase precipitation to a maximum of > 2200 mm, the annual average being about 2500 mm. Higher up, the rainfall decreases due to the lower moisture content of the trade wind inversion. This higher altitudes are still comparatively wet but also steep so that forests or National Parks are the best land use. Due to the demands of increasing land pressure, the lower, herbaceous parts of the Tropical Alpine Zones may in future be used by those farmers living below the forests for seasonal grazing of livestock.
Downwards from the 2500 m level, although rainfall decreases with altitude to about 1600 mm in a 15 km. broad zone at the 1600 m level, there is no real shortage of water which would lead to water stress for the crops. The main reasons for this relatively high water availability are the low evaporation due to the typical cloud cover and the frequent morning mists, and the high water holding capacity of the deep volcanic soils which ensure that a high proportion of the rainfall is available to plants.
Below that altitude, the rainy seasons become considerably shorter, with an expectation of rainfall of less than 300 mm. in 20 out of 30 years for the first rains, and less than 250 mm. for the second rains. Considering this fact, it becomes clear that maize crop failures will occur regularly and that irrigation is advantageous in that area (e.g. Mwea Tebere).
In the Agro-Ecological Zones Map 23.0.3, the typical sequence from the Tea- Dairy Zone LH 1 through the three different Coffee Zones UM 1, 2 and 3, to LM 3 (Cotton Zone) and LM 4 (Marginal Cotton Zone) is shown for the District, similar to the sequence in Murang'a District.
The 66% reliability of rainfall, i.e. amount surpassed in 20 out of 30 years, is shown in Map 23.0.1 for the first rains and in Map 23.0.2 for the second rains. Evaporation, varying with altitude, ranges between 1800 mm. at 1400 m., and 1300 mm. at 2500 m. The mean annual temperatures are about 20°C at 1400 m and 12.0°C at 2500 m, respectively.
A summary of climatic data is compiled in Table 23.0.1, which can be used as a key to the Agro-Ecological Zones Map 23.0.3.
The UM"2 Agro-Ecological Zone is represented by the Kerugoya Trial Site (23.1). The Tea-Dairy Zone (LH 1) is represented by the two trial sites in Nyeri District. Zone UM 1 is covered by the Githunguri Trial Site in Kiambu District and UM 4 by the Makuyu Trial Site in Murang'a District. The Lower Midland Zones (LM 3 and 4) are represented by Trial Sites in Erabu and Meru Districts. The Marginal Coffee Zone (UM 3) is not represented by any of the FURP first priority trial sites. Zones UH 0 and LH 0 are Forest Zones and the Tropical Alpine Zones (TA 0, I,II) belong to the Mount Kenya National Park.
- 0.3 - 37TE 37^30-
Map 23.0.1 KIRINYAGA 66% RELIABILITY OF RAINFALL IN AGROHUMID PERIOD OF FIRST RAINS (March-Sept, or less) Mt. Kenya Amounts in mm, surpassed norm, in 20 out of 30 years V \ Ml. Kenya Nal. Park
1° c
Broken boundaries are uncertain because ol lack ol rainfall records 25 km to 20
Nal Ag> Labs . German Agr Team. B. Jaetzold
- 0.4 - 37^ E
Map 23.0.2 KIRINYAGA 66% RELIABILITY OF RAINFALL IN AGROHUMID PERIOD OF SECOND RAINS (Oct.-Feb. or less) MI. Kenya Amounts in mm. surpassed norm, in 20 out of 30 years enya Nal. Park
MBU
25 km Broken boundaries are uncertain 5 K) IS 20 because o( lack ol rainfall records Nat Agr Labs Gorman Agr tram. R Jai'l/.old
-0.5- Table 23.0^1 : Climate in the Agro-Ecological Zones of Kirinyaga District
Agro-Ecological Su ozone Altitude Annual mean Annual av. 66 % reliability 66% reliability Zone in m temperature rainfall or rainfall" of growing period in°C in mm 1st rains 2nd rains 1st rains ' 2nd rains Total'') in nun in mm in days in days in days
TAO National Park Rocks and Glaciers
TAI + 11 Tropical-Alpine National I'ark Moor- and Hcathlands
UHO lorest Reserve l:orcst Zone
LHO Torest Reserve l:oresl Zone
LH 1 l/vl r, m 1 760-2 130 17.8- 14.5 1 700-2 150 900-1 100 500-620 210 or more 140-150 250-260 Tea-Dairy Zone
UM 1 f lim 1 520-1 820 19.3 17.5 1 400 1 700 750-950 430-520 200 or more 130-150 230-250 Coffee-Tea Zone
UM 2 m/l i m/s 1 220 1 500 600-800 400-460 170 or more 115-130 285-300 Main Coffee 1 400 1 580 20.1-19.0 m + s/m 1 200 1 250 580-620 380-430 160 or more 105-115 Zone
UM 3 Marginal Coffee m/s + s 1 310-1 400 20.6-20.1 1 100 1 250 450-580 350-400 120-140 85-105 - Zone
UM 4 s/m + s 950-1 200 420-500 330-350 105-115 85-105 Sunflower- 1 280-1 340 20.9-20.4 s + s 950 960 400-420 320-330 90-105 85-105 - Maize Zone
LM 3 s/m + s 950-1 200 420-500 320-350 105-115 85-100 - 1 220-1 280 21.2-20.9 Cotton Zone s + s 900 1 100 380-460 280-330 85-105 80-95
LM4 s + s/vs 850-950 330-400 250-300 85-105 75-85 Marginal 1 090-1 220 22.0-21.2 s/vs•+ vs/s 800-850 300-350 200-250 75-85 55-75 - Cotton Zone
LM5 Lower Midland Small transitional strip Livestock-Millet Zone
' Amounts surpassed normally in 6 out of 10 years', falling during (he agro-humid period which allows growing of most cultivated plants. ^' More if growing cycle of cultivated plants continues into the period of second rains.
3) Only added if rainfall continues at least for survival (>0.2 Iio) of most long term crops. Source: Jaetzold R., and H. Schmidt, eds. (1982): Farm Management Handbook of Kenya, volume Il/8 Central Kenya, page 686.
- 0.6 - MAP 23.0.3 AEZs AND TRIAL SITES IN KIRINYAGA DISTRICT
37° E 37^30 E
• Site of first priority
231 Kerugoya
AGRO-ECOLOGICAL ZONES
EMBU
S/V5 + VS/S
National Park
Forest Reserve soil boundary, see Map 4
Steep slopes t unsuitable for cult, (only marked outside Nat Parks or Forest Res. )
Belt of A. E. Zones — — — Broken zonal boundaries are uncertain or A. E. Zones — mean transitional strips Subzones Climalic data for AEZ formulas see tables II. 1-2, II 1-4 and 23.01 •HK?
KtiRTI L1ZER USt kbCUMMLNÜAT I ON PROJECT M987) Ministry of Agriculture National Agricultural Laboratories German Agricultural Team
10 15 20 25 km District: Kirinyaga General Aspects 23.0
The soils of Kirinyaga District are shown in Map 23.0.4. The soils fit entirely into the Aberdares-Mount Kenya Toposequence which has paramount influence on the soil genesis in Meru, Embu, Kirinyaga, Nyeri, Muranga, Nyandarua and Kiambu Districts.
Mountain units MV1 (dystric Histosols and Lithosols) and MV2 (humic Andosols, partly lithic phase) constitute the Northern "triangle" of the District, below which volcanic footridges stretch from east to west (units RBI,2 and 3). In the southern parts of the District, plateaus and high-level structural plains (units LB1,2 and 8) are prevalent. All these soils are developed on rich, basic igneous rocks. The major units are shown below.
===== Soils developed on basic igneous rocks.
Unit RBI, North of Kerugoya: ando-humic Nitisols, with humic Andosols (cf. Trial Site 22.2. Nyeri District): - Unit RB2, Embu-Kerugoya-Baricho area: humic Nitisols (Trial Site 23.1): Unit RB3, Sagana area: eutric Nitisols with some shallower inclusions (cf. Trial Site 21.2. Muranga District): - Unit LB1: very deep nito-rhodic Ferralsols (cf. Trial Site 24.2. Embu District): - Unit LB2 constitutes a transition to heavy-textured soils with swelling properties: verto-eutric Nitisols; Unit LB8: heavy-textured and poorly drained soils, accommodating amongst others Mwea Irrigation Scheme: pellic Vertisols, in places saline (proposed Trial Site 23.2).
The basic climatic and soil designations referring to the trial site in Kirinyaga District are summarized in Table 23.0.2.
Table 23.0.2: Agro-Ecological Zone and Soil Classification of the Trial Site in Kirinyaga District
Site Site Agro-Ecological Soil Classification No. Name Zone
23.1 Kerugoya Main Coffee Zone humic NITISOL (UM 2)
- 0.9 - District : Kirinyaga General Aspects 23.0
2. Location of the Trial Site and Criteria for its Final Position
In the Kirinyaga District, one first priority site was selected as shown in Map 23.0.4. The trial plot is rectangular and uniform and accessibility is good, as the site is situated next to Kerugoya town, which also means that the demonstration effect is high.
The nearest long-term rainfall-recording station: 09037031, Kerugoya Water Office is located 1.2 km N of the trial site. Farmers' fields are within close range and have soils which adequately resemble the soils of the main plot.
The criteria for the final position of the trial site are listed in Table 23.0.3, which is self-explanatory. Criteria have been rated very good (1), good (2), moderate (3), poor (4) or non-relevant (nr).
Table 23.0.3 Ratings of Criteria Used for Trial Site Selection in Kirinyaga District
Criterion Site number
23.1
1. Representativeness Agro-Ecological Zone 1 2. Representativeness Soils 1 3. Representativeness Topography 2
4. Adequacy of size and shape of the trial plot 2 5. Absence of trees and hedges 2 6. Absence of rocks and boulders 1 7. Absence of termite mounds 1 8. Uniformity of previous land use 2
9. Accessibility 1 10. Demonstration effect 1 11. Proximity to a long-term rainfall station 2
12. Availability of storage facilities 3 13. Availability of sturdy fences 3 14. Availability of housing facilities for T.A.s 1
15. Farmer's willingness to cooperate 2 16. Security - theft 2 17. Security - intruding animals 2
18. Proximity of on-farm trials 2 19. Representativeness of soils at on-farm trials 1
- 0.10 - MAP 23.0.4 SOILS AND TRIAL SITES IN KIRINYAGA DISTRICT 371E 37°l30
• Site of first priority 23 1 Kerugoya
SOURCE El Exploratory Soil Map of Kenya,1980 (scale 1 :1 ,000,000)
KEY RBI soil mapping code — soil boundary WQ towns and major villages •=- -rr. tarmac road other all-weather roads district boundary _ national park boundary — - river
For LEGEND See APPENDIX
1! S EMBU
>30'
3*2
FERTILI/.tlR UKt: KKL'OMMENDATJ ON PROJECT (1'J87) Ministry oE Agriculture National Agricultural Laboratories German Agricultural Team
10 25 km District: Kirinyaga General Aspects 23.0
3. Names and Addresses of Government Officers Involved in FURP Activities
The names and addresses of the agricultural staff members of the district are listed in Table 23.0.4.
Table 23.0.4: Names and Addresses of Government Officers in the District
OFFICER SITE NAME P.O. BOX TEL. NO.
DISTRICT D.C. A. Oyier D.A.O. J. Ndwati 392- 91- D.C.O. P.K. Cheruiyot Kerugoya Kerugoya D.E.C. B.M. Kitheka
DIVISION Div. Ext. 23.1 Miss M.M. Juma 392- 33- Officer Kerugoya Baricho Loc. Ext. 23.1 P.K. Mbadi- 392- 91- Officer Kerugoya Kerugoya Technical 23.1 Michael Njuith Assistant
Period of site selection in the District: June 1986.
- 0.13 - District: Kirinyaga General Aspects 23.0
4. Trial Design and Execution Plan, Kirinyaga.
(Full details of the methodology for carrying out the trials are shown in Chapter IV of the main report).
Selection of Crops: The proposed crop sequences in each of the three modules, for the Kirinyaga Trial Site are:
Site 23.1 Kerugoya, RAINY SEASONS Kirinyaga 1st, Long, March 2nd, Short, Oct.
51 Standard Maize Hybrid 511 Katumani C.B. 52 Maize & Beans H.512 +GLP 2 Beans K.C.B.+GLP 2 Beans 53 Potat./Cabb.; Beans Annet/Copenhagen GLP 2 Beans
The 1st sequence or module is continuous, pure maize, twice/year. The 2nd is intercropped maize and beans also twice/year. The 3rd is potatoes or cabbages in the 1st rains, and beans in the 2nd rains. In October 1986 when starting up the site, Annett potatoes were planted in this module.
Each module contains 2 experiments, namely Experiment 1 and Experiment 2. Experiment 1 is a 4N x 4P factorial, with 2 replications in each module. Experiment 2 is a 2NP x 2K x 2L x 2 FYM factorial, also with 2 replications in each module.
Each module thus consists of 64 plots, and the total for the 3 modules is 192 plots.
FYM will be applied only during the October Rains, as the trial here started in October. Mineral fertilizers will be applied during both rains. Where maize and beans are intercropped, the fertilizer will be given to maize. The intercropped beans will not receive any fertilizer directly at planting, but will "scavenge" from the maize and from residual fertilizer left after the first season.
5. Areas in Kirinyaga District Represented by FURP Trial Sites
The aim of FURP Phase I is to select trial sites which, as far as possible, are representative of the agriculturally high and medium potential areas of Kenya. This consideration constituted the backbone for making decisions as to where to establish these FURP trial sites.
Two representativeness maps are drawn per District. One refers to the soils only (Map 23.0.5: Groupings of Soil Mapping Units), and in the second one (Map 23.0.6) Agro-Ecological Units (AEUs) are shown in which, according to the information available, the soils and the climate can be considered homogeneous.
Map 23.0.5 shows the representativeness of FURP trial sites for Kirinyaga District only as far as soils are concerned.
- 0.14 - District: Kirinyaga General Aspects 23.0
The explanation for this Map shows nine generalized "Groupings of Soil Mapping Units". These Groupings have the same or similar soil properties and, as such, represent a specific soil environment, typified by one of the FURP trial sites.
The codes in the explanation to Map 23.0.5 refer to a specific trial site (23.1, etc.) and to a specific degree of representativeness of soils (A, B+, B-). The combination of both forms a "Soil Representativeness Code". Unit 23.1.A, for instance, covers an area which is highly represented (A) by the Kerugoya Trial Site (23.1). Unit 22.2.B- covers an area which is moderately represented (B) by the Chehe Trial Site, Nyeri District (22.2), although information on soil properties reveals slightly less favourable conditions in the represented area in Kirinyaga District than at Chehe itself (B-).
The explanation to Map 23.0.5 also lists those units of the Soil Map (Map 23.0.4) which are considered in the various groupings. A breakdown of soil properties referring to the Groupings of Soil Mapping Units is given as part of Table 23.0.5.
The soils of Kirinyaga District are well represented by the FURP trial sites. This is testified by Map 23.0.5 which shows a very high A and B cover. The different soils of the Aberdares-Mount Kenya Toposequence, discussed in Sub-Section 23.0.1, are represented in the following Groupings:
Volcanic Footridges: upper slopes: humic Andosols (Grouping 22.2.B-) and ando-humic Nitisols (Grouping 22.2.A);- middle slopes: humic Nitisols (Grouping 23.1.A); lower slopes: eutric Nitisols (Grouping 21.2.A);
Plateaus and high-level Structural Plains : well drained, red, nito-rhodic Ferralsols (Grouping 24.2.A), well drained, dark reddish brown, verto-eutric Nitisols (Grouping 21.2.B+), and imperfectly drained, black, pellic Vertisols (Grouping (23.2).A).
Trial Site 23.2 is put in brackets, as it has not yet been identified. It is, however, advisable to have a site on the rather extensive Vertisol area occurring in Central Province and Embu District. As long as the site is not operational, the area should be considered as C (not represented by a trial site).
Areas which are not represented by any one trial site with respect to soils are coded C. This involves some scattered hills and the highest parts of Mount Kenya.
The second representativeness map, Map 23.0.6, shows the integrated representativeness of FURP trial sites involving both soils and climate. The map units are named "Agro-Ecological Units" and they represent a specific soil-climate environment, typified by FURP trial sites.
All combinations of the different soil-climate environments occurring in Kirinyaga District are shown in the Agro-Ecological Unit Map (Map 23.0.6)
- 0.15 - District: Kirinyaga General Aspects 23.0
and are explained in Table 23.0.5. The codes for the Agro-Ecological Units consist of three parts: site, soil representativeness and climatic representativeness. Site and soil representativeness are taken from Map 23.0.5. In addition, Map 23.0.6 and Table 23.0.5 indicate the codes which refer to the representativeness of the climatic environment (small letters).
Several degrees of representativeness are given according to the prevailing temperature regime and the rainfall in the agro-humid period of the long rains.
All areas in Map 23.0.6 marked with code "a" (highly representative) are within the same temperature belt and receive the same amount of rainfall (± 10%) in the agro-humid period of the long rains as the trial site to which the code refers.
/The map units marked with code "b" (e.g.: b-H-, b+- ,b+*) are only modera- tely represented by trial sites. In the AEU 23.1.A.b++, for instance, the soils are highly represented by the Kerugoya Trial Site (23.1.A), but the climate (b++) indicates that this Agro-Ecological Unit belongs to the next warmer temperature belt and receives 10-20% more rainfall than the Kerugoyà Trial Site.
Areas which are not represented by any one trial site, i.e. soils and/or climate not represented by any site, are coded 0.
The criteria set for sub-division of the various degrees of representativeness with respect to soils and climate are further elaborated upon in Chapter IV.2 of the main report.
- 0.16 - EXPLANATION TO MAP 23.0.5
Degree of representativeness Groupings of soil mapping units
A highly representative Soil Representativeness Soil Map Units Code (Map 23.0.5) 1> Included (Map 23.0.4) B+ moderately representative (soils of map unit are slightly more favourable than soils at the trial site) 21.2.A RB3
B- moderately representative 21.2.B+ LB2 (soils of map unit are slightly less favourable than soils at the trial site) 22.2.A RB1
C non-representative 22.2.B- MV2 I o 23.1.A RB2
00 Trial sites (23.2).A LB8 I 21.2 Makuyu - Murang'a District 24.2.A LB1 22.2 Chehe - Nyeri District 23.1 Kerugoya - Kirinyaga District 24.2.B- UU1 (23.2) 2> Muea-Tebere - Kirinyaga District 24.2 Gachoka - Embu District C others
1) Digits show trial site number; letters indicate degree of representativeness. For cartographic reasons, Soil Representativeness Code C is not indicated for the many scattered hills, bottomlands, and flood plains. These areas should be considered inclusions of units with Representativeness Codes A, B+, and B-. 2) Site has not yet been identified. See Subsection 23.0.5 for explanation. MAP 23.0.5 GROUPINGS OF SOIL MAPPING UNITS REPRESENTED BY TRIAL SITES IN KIRINYAGA DISTRICT 37° E 37°l30'
• Site of first priority 23.1 Kerugoya soil groupings mapping code . soil groupings boundary
SOURCE El Exploratory Soil Map of Kenya, L980 (scale 1 :1,000,000)
KEY RBI soil mapping code -_ „ soil boundary £• towns and major villages ^z= tarmac road other all-weather roads district boundary „. _ national park boundary — river
For LEGEND See APPENDIX PAOB
EMBU
-13*7
P1ÎRTILIZER USL KKCOMMENDAT] ON PROJECT (19Ö7! Ministry of Agriculture National Agricultural Laboratories German Agricultural Team 25 km 10 20 Table 23.0.5: Hajor Soil Properties and Cliiatic Conditions of the Agro-Ecological Units in the ürinyaga District
Agro-Ecological Unit Soil properties Cliiatic Conditions Site Soil Cliiate drai- eff. nutr. top- loist. classi- teap.l) teip. 1) rainfall - Agro-Ec, Agro-Ec. Ho, Code Code nage depth avail, soil st.cap, fication •ean ann. lean lin. 661 prob.2) Subtone Zone 3)
21.2. A « ed i-h 0 vh eu Ni (t ni-ch Ca • ch Ac • ch Lu) bt« 21-24 14-17 370-450 4 s/its to LH 3-4 Sts/VB bH 21-24 14-17 450-490 4 s/its LH 3 b*** 18-21 11-14 450-490 4 i/sts to UH 3-4 s/ats b*x 18-21 11-14 490-530 4 i/sts UH 3 21.2. Bt « vd h 0|-lh) vh ve-eu Ni (t to Hi) 21.2. B- bM 18-21 11-14 450-490 4 s/nts UH 4 b»i 18-21 11-14 490-530 4 i/sts UK 3 bt» 21-24 14-17 370-450 4 9/its to LH 3-4 Sts/vs bt- 21-24 14-17 330-370 4 sts/vs to LH 4 S/V8UB/S b»x 21-24 14-17 290-330 4 s/vatvs/s LH 4-5 22.2. A « ed h Iah vh an-hu Ni (t ha An) a 15-18 8-11 880-1080 1/vl-a LH 1 b*- 18-21 11-14 780-880 f 1 i i UK 1 btx 18-21 11-14 680-780 f 1 i i UH 1 bt* 18-21 11-14 880-1080 f 1 i i UH 1 22.1. B- a 15-18 8-11 880-1080 1/vl-a LH 1 b»t 15-18 8-11 1080-1180 p to l/vl--i LH 0-1 b-* 10-15 3-8 880-1080 UH 0 b-t 10-15 3-8 1080-1180 UH 0 b-i 10-15 3-8 1180-1280 UH 0 22.2. B- v vd i-h 2ah vh hu An 23.1. A « ed h Iah vh hu Hi a 18-21 11-14 665-8155 l/l i i/s UH 2 b*- 18-21 11-14 590-665 .iti/i UH 2 b*x 18-21 11-14 515-590 n/ats UH 3 (23.2|.A i vd h 0 h-vh pe Ve a 21-24 14-17 310-390 5) sts/vs to LH 4 s/vstvs/s b*t 21-24 14-17 390-430 5) sts LH 3 b»- 21-24 14-17 270-310 5) s/vs4vs/s LH 4 24.2. A • vd 1 0 h-vh ni-rh Fe a 21-24 14-17 320;400 6 sts to LH 3-4 steht b*t 21=24 14-17 400-440 6 s/its LH 3 b-t 18-21 11-14 400-440 6 s/its UH 4 24.2. B- » id-d 1 0 i-h rh « or Fe 26.4. A bu 14-17 14-17 290-320 7) s/vstvs/s LH 4 C soil not representative 0 soil and/or cliiate are not representative
ley: Drainage loiature storage capaciti se soieahat excessive vh ver; high ) 160 ••. » well h bieb 120-160 il. a« loderatelv «ell • loderate 80-120 ••. i iaperfect 1 low ( 80 u. t poor
Effective soil death nutrient availability 1) Teiterature («C| (differentiated according to AEZ belts) ed extreiely deep > 180 ci, h high vd verr deep 120-180 ci. i loderate 2) Rainfall 6EX probability (in u.| d deep 80-120 c». 1 lo« -referring to agro-huiid period of id «oderately deep 50- 80 ci. vl very lo« long rains only; sh shallow 25- 50 ci, Specification given -for definition of rainfall ranges see vsh very shallo« < 25 ci. in Chapter IV.2 explanation to Hap ...0.6; (lain report) -66X probability leans that aiount of rainfall «ill be exceeded in at least Topsoil properties Soil claiaificatioa 20 out 30 years. li huiic (base Ni Nitisols 10 lollic ni-ch nito-chroiic 3) Agro-Bcologic»! Subtone saturation >50 X) An Andosols hu huiic ni-rh nito-rhodic - approximative indication only, since ah acid huiic (base Ca Caibisols or orthic an-hu ando-huiic subtones are not directly related to saturation <50J) Lu Luvisols rh rhodic ve-eu verto-eutric aiount of rainfall; 2 thick (30-60 ci.) Ac Acrisols ch chroiic pe pellic -"—' in fonula leans 'tolloved by'; 1 thin (<30 ci.) Fe Ferralsols eu eutric see Chapter [V in lethodology; 0 non-huaic Ve Veriiaola - Agro-ecological tones and subtones are shovn in Hap..,0,3. 4) Kid Karch-e. of June. S) If Bite is situated near the 350 •• - isohyete. 6) B. of Harch-b. of July. 7) B. of Harch-b. of Jane.
- 0.21 - EXPLANATION TO MAP 23.0.6
Soil Codes Climatic Codes
_ A = highly representative a highly representative;,i.e. same Agro-Ecol.Zones Belt and long rains < +/-10%) as at trial site
b moderately representative = B+ = moderately representative (soils of map unit are slightly more ++ = 1 AEZ Belt warmer, long rains 10-20% higher favourable than soils at the trial site) +• = 1 AEZ Belt warmer, long rains similar (+/-10%) +- = 1 AEZ Belt warmer, long rains 10-20% lower B- = moderately representative -+ = 1 AEZ Belt cooler, long rains 10-20% higher (soils of map unit are slightly less -• = 1 AEZ Belt cooler, long rains similar (+/-10%) favourable than soils at the trial site) — = 1 AEZ Belt cooler, long rains 10-20% lower •+ = AEZ Belt the same, long rains 10-20% higher I •- = AEZ Belt the same, long rains 10-20% lower o xx = 2 AEZ Belts warmer long rains 20-30% higher Trial sites xx = 2 AEZ Belts cooler long rains 20-30% lower
21.2 Makuyu (Murang'a District) 22.2 Chehe (Nyeri District) 23.1 Kerugoya (Kirinyaga District) (23.2) Mwea-Tebere (Kirinyaga District) 24.2 Gachoka (Embu District) Areas not represented
0 = • not represented bysoils and/or climate
For further explanation see Table 23.0.5 MAP 23.0.6 AGRO-ECOLOGICAL UNITS REPRESENTED BY TRIAL SITES IN KIRINYAGA DISTRICT 0 30 371 E 37 " ' E
• Site of first priority 23.1 Kerugoya
. agro-ecoloqical units boundary
SOURCE El Exploratory Soil Map of Kenya,1980 (scale 1:1,000,000)
KEY RBI soil mapping code — soil boundary t# towns and major villages — - tarmac road -"=- other all-weather roads district boundary national park boundary — river forest reserve boundary
For LEGEND See APPENDIX For EXPLANATION see PREVIOUS PAGE and TAB7£ 23.0.5
222
J! S
21.2 b+J!
1
FERTILIZER USE RUCOMMfcNDATION PROJECT (1987) Ministry of Agriculture National Agricultural Laboratories German Agricultural Team
10 15 20 25 km District: Kirinyaga General Aspects 23.0
LEGEND TO THE SOIL MAP OF KIRINYAGA DISTRICT
1—Explanation of first character (physiography) H Mountains and Major Scarps H Hills and Minor Scarps L Plateaus and High-Level Structural Plains R Volcanic Footridges ü uplands, upper, Middle and Lower Levels
2—Explanation of second character (lithology): B Basic and Ultra-Basic Igneous Rocks (basalts, nepheline phonolites; older basic tuffs included) Ü Undifferentiated Basement System Rocks (predominantly Gneisses) V undifferentiated or Various Igneous Rocks
3—Soil descriptions MV1 Imperfectly drained, shallow to moderately deep, dark greyish brown, very friable, acid huiic to peaty, loan to clay loam, with rock outcrops and ice in the highest parts dystric HISTOSOLS, lithic phase; with LITHOSOLS and Rock Outcrops HV2 Well drained, very deep, dark reddish brown to dark brown, very friable and smeary, clay loan to clay, with a thick acid humic topsoil; in places shallow to moderately deep and rocky huraic ANDOSOLS, partly lithic phase HD1 Somewhat excessively drained, moderately deep, red, very friable, sandy clay loam to sandy clay; in places rocky ferralic CAMBISOLS; with rhodic or orthic FERRALSOLS and Rock Outcrops HDC Complex of: excessively drained to well drained, shallow, dark red to brown, friable, sandy clay loam to clay; in many places rocky, bouldery and stony and in places with an acid humic topsoil dystric REGOSOLS, lithic phase; with LITHOSOLS, humic CAMBISOLS, lithic phase and Rock Outcrops LB1 Well drained, very deep, dark red, very friable clay nito-rhodic FERRALSOLS LB2 Well drained, very deep, dark reddish brown to dark brown, friable to firm, clay; in places with a humic topsoil verto-eutric NITISOLS; with mollic NITISOLS LB8 Imperfectly drained, very deep, dark grey to black, firm to very firm, bouldery and stony, cracking clay; in places with a calcareous, slightly saline deeper subsoil pellic VERTISOLS, stony phase and partly saline phase; RBI Well drained, extremely deep, dark reddish brown to dark brown, friable and slightly smeary clay, with an acid humic topsoil ando-humic NITISOLS; with humic ANDOSOLS
- 0.25 - District: Kirinyaga General Aspects 23.0
RB2 Well drained, extremely deep, dusky red to dark reddish brown, friable clay, with an acid hunic topsoil hunk NITISOLS RB3 Well drained, extremely deep, dusky red to dark reddish brown, friable clay; with inclusions of well drained, moderately deep, dark red to dark reddish brown, friable clay over rock, pisoferric or petroferric material eutric NITISOLS; with nitö-chromic CAHBISOLS and chroiic ACEISOLS and LÜVISOLS, partly lithic, pisoferric or petroferric phase UU1 Well drained, moderately deep to deep, dark red to yellowish red, friable, sandy clay loam to clay rhodic and orthic FERRALSOLS; with ferralo-chromic/orthic/ferric ACRISOLS NOTES: 1. mollic Nitisols and chrono-luvic Phaeozens: soils are equally important 2. mollic Nitisols, with chromo-luvic Phaeozens: Nitisols are 'prevalent 3. in places: in <30t of the area 4. in many places: in 30-50% of the area 5. predominantly: in >50l of the area 6. deeper subsoil: below 80 en.
- 0.26 - District: Kirinyaga Trial Site 23.1: Kerugoya
Contents of Chapter 23.1:
Detailed Description of the Kerugoya Trial Site
Page
1. Geographical and Additional Technical Information 1.4 1.1 'Final Position of the Trial Site 1.4 1.2 Sketch of the Trial Site 1.5 1.3 Physiography 1.7 1.4 Vegetation, Past and Present Land Use 1.8 1.5 Names and Addresses of Government Officers from the Division and Farmers Involved in FURP Activities 1.9
2. Climate 1.10 2.1 Prevailing Climatic Conditions 1.10 2.1.1 Agro-Climatic Classification of the Area Represented 1.10 2.1.2 Relevant Meteorological Data 1.11 2.1.3 Crop Suitability from the Climatic Point of View 1.15 2.2 Proposal for the Monitoring of Agro-Climatic Conditions in Phase II 1.20
3. Soils 1.21 3.1 Survey Data 1.21 •3.1.1 Brief Soil Description and General Information on the Soil 1.21 3.1.2 Detailed Profile Description and Soil Classification 1.22 3.1.3 Soil Sampling 1.24 3.2 Laboratory Data 1.24 3.3 Evaluation of Soil Data 1.29 3.3.1 Literature References and Soil Correlation 1.29 3.3.2 Representativeness 1.29 3.3.3 Variability of Soil Properties within the Trial Site 1.30 3.3.4 Fertility Status of the Soil 1.31 3.3.4.1 Soil Profile and Global Fertility Rating 1.31 3.3.4.2 Soil Fertility Assessment of Composite Samples 1.32 3.4 Sampling Programme for Laboratory Analysis 1.34 3.4.1 Soil Samples 1.34 3.4.2 Plant Samples 1.35 3.4.3 Other Samples 1.35
4. Conclusions from the Analyses of Climate and Soils 1.35 4.1 Moisture Availability 1.35 4.2 Nutrient Availability in Relation to Possible Fertilizer Requirement 1.36 4.3 Other Relevant Land Qualities 1.37
5. Trial Design and Execution Plan 1.38
- 1.1 - District: Kirinyaga Trial Site 23.1: Kerugoya
List of Tables1)
Page
Table 23.1.1 Physiography of the Kerugoya Trial Site 1.7
Table 23.1.2 Vegetation, Past and Present Land Use 1.8
Table 23.1.3 Names and Addresses of the Divisional Staff Members and
Farmers of the Kerugoya Trial Site 1.9
Table 23.1.4 Data of the Nearest Long-Term Rainfall Station 1.12
Table 23.1.5 Temperature 1.13
Table 23.1.6 Potential Evaporation (Eo) . 1.13
Table 23.1.7 Agro-Climatological Crop List for Kerugoya 1.15
Table 23.1.8 Crop Development Stages and Crop Coefficients 1.17
Table 23.1.9 Detailed Profile Description of the Kerugoya Trial Site 1.23
Table 23.1.10 Analytical Results (physical and chemical analyses) 1.25
Table 23.1.11 Analytical Results (chemical analyses, trial plot) 1.26
Table 23.1.12 Analytical Results (chemical analyses, farmers' fields) 1.28
Table 23.1.13 Soil Correlation with Respect to the Kerugoya Trial Site 1.29
Table 23.1.14 Evaluation of Mehlich Analysis Data According to NAL Standards 1.34
1) See Footnote next page.
- 1.2 - District: Kirinyaga Trial Site 23.1: Kerugoya
List of Figures 1)
Page
Figure 23.1.1 Demarcation of the Kerugoya Trial Site 1.4
Figure 23.1.2 Access Map of the Kerugoya Trial Site 1.5
Figure 23.1.3 Map of the Trial Plot, Kerugoya 1.6
Figure 23.1.4 Location of Farmers' Fields for On-Farm Trials, Kerugoya 1.7
Figure 23.1.5 Rainfall and Potential Evaporation 1.14
Figure 23.1.6a Water Requirement and Availability for Maize H 512, First Rains - 1.18 Figure 23.1.6b Water Requirement and Availability for Maize Katumani C.B., Second Rains 1.19
Figure 23.1.7 Location of Composite Sampling Blocks and Profile Pit at the Kerugoya Trial Plot 1.24
1) Numbering mode of Tables and Figures: First Number: District Number Second Number: Trial Site Number Third Number: Number of Table or Figure within Chapter.
- 1.3 - District: Kirinyaga Trial Site 23.1: Kerugoya
1. Geographical and Additional Technical Information
1.1 Final Position of the Trial Site
The position of the site at Kerugoya is shown in Figure 23.1.1, extracted from Map No. 135/2 - Embu. Its UTM grid coordinates are E 08.6 and N 42.9. The elevation is 1480 m. Further details on the final position are shown in Figure 23.1.2 and the sketch map of the trial plot in Figure 23.1.3.
£
Figure 23.1.1: Demarcation of the Kerugoya Trial Site on the 1:50,000 Topographic Map
- 1.4 - District: Kirinyaga Trial Site 23.1: Kerugoya
1.2 Sketch of the Trial Site.
The location of and the access route to the Kerugoya site are shown in Figure 23.1.2 and the map of the trial plot in Figure 23.1.3.
Kerugoya
0.5 1.5 !Km
Figure 23.1.2: Access Map of the Trial Site, Kerugoya
- 1.5 - District: Kirinyaga Trial Site 23.1: Kerugoya
FURP pins.. Hedge Fence 10 20 30 40 50(n Scale
Figure 23.1.3: Map of the Trial Plot, Kerugoya
- 1.6 - District: Kirinyaga Trial Site 23.1: Kerugoya
The approximate location of the on-farm trials is indicated in Figure 23.1.4.
Karatina
Kerugoya
Kuj.us Baricho trial plot 23.1
Figure 23.1.4: Location of Farmers' Fields for On-Farm Trials, Kerugoya
1.3 Physiography
Information on the physiography of the trial site and its surroundings is summarized in Table 23.1.1 below.
Table 23.1.1: Physiography of the Kerugoya Trial Site
Elevation 1480 m.
Landform lower volcanic: footridges
Physiographic position of the site concave upper and middle slope
Topography of surrounding country undulating to hilly (steepest slopes 16-30%)
Slope on which trial plot is sited 3-6%
Aspect NE
Microtopography nil
- 1.7 - District: Kirinyaga Trial Site 23.1: Kerugoya
1.4 Vegetation, Past and Present Land Use
Information on vegetation and on past and present land use is summarized in Table 23.1.2 below:
Table 23.1.2: Vegetation, Past and Present Land Use of the Kerugoya Trial Site
Vegetation Cultivated Cordia-Bridelia types from lower moist intermediate forest
Cropping system
(a) cleared since: 1959 (b) crops grown: maize (H 511, 613) potatos,beans (RoCo, CaWo) (c) fallow periods: none (d) present land use: maize
Inputs
(a) mineral fertilizers: 20:20:0, CAN, ASN, DAP (b) organic manure: not since 1979 (c) means of land preparation: tractor or oxen (d) means of weeding: manual (e) frequency of weeding: once per crop stand (f) other capital inputs: DDT against stalk-borer (g) level of know-how: moderate to high
Produce
(a) maize no information
Livestock none
Remarks
Outstanding performance of maize was observed during site selection. Low frequency of weeding due to labour shortage
- 1.8 - District : Kirinyaga Trial Site 23.1: Kerugoya
1.5 Names and Addresses of Government Officers Involved in FURP Activities
Names and addresses of the divisional staff members and of all farmers involved are given in Table 23.1.3.
The codes used for the additional "on-farm" farmers refer to the location of their farms as indicated in Figure 23.1.4.
Table 23.1.3: Names and Addresses of Divisional Staff Members and of Farmers of the Kerugoya Trial Site
Divisional Name Address Staff
D.E.O. Miss M.M. Juma Box 392. Kerugoya L.E.O. P.K. Mbadi ti T.A. Michael Njueth H
Farmers Name Address
Trial plot Stanley Kabui Ngethe Box 12. Kerugoya
LOCATION: Inoi SUB-LOCATION: Ndimi
On-Farm trials Name Remarks
23.1.A Bernard Ithiga 23.1.B David Mwobe 23.1.C Rakari Waniiku 23.1.D Leonard Ndeguor 23.1.E Aram Mureithi 23.1. F Sabstian Njiru 23.1.G Philip Mbogo 23.1.H Nahashor Ngige 23.1.1 James Ngacha
Period of site selection: June 1986.
- 1.9 - District: Kirinyaga Trial Site 23.1: Kerugoya
2. Climate
2.1 Prevailing Climatic Conditions
2.1.1 Agro-Climatic Classification of the Area Represented by the Kerugoya Trial Site
The following brief climatic description refers to existing information:
ACZ : 14 (H.M.H. BRAUN, 1982)1)
AEZ : UM 2, m/1 i m/s (R. JÄTZOLD, 1983)2)
Next long-term rainfall station: 09037031, Kerugoya Water Office.
Agro-Climatic Zone (ACZ):
Moisture availability Zone II (r/Eo): annual average precipitation is 65- 80% of the potential evaporation (Eo).
Temperature Zone 4: mean annual temperature is 18-20°C
Agro-Ecological Zone (AEZ):
UM 2 = Main Coffee Zone
UM = Upper Midland Zone: mean annual temperature 18-21°C, mean minimum 11-14°C
2 = sub-humid; annual average precipitation is >65-80% of the potential evaporation (Eo)
Sub-zone according to growing periods for annual crops (calculated for a "normal" crop in 60% probability) m/1 i m/s = with a medium to long cropping season, intermediate rains, and a medium to short one.
1) According to H.M.H BRAUN in: W.G. SOMBROEK, et al. (1982): Exploratory Soil Map and Agro-Climatic Zone Map of Kenya, scale 1:1,000,000 - Rep. El, Nairobi
2) According to R. JÄTZOLD and H. SCHMIDT, eds. (1983): Farm Management Handbook of Kenya, Vol. II/B CENTRAL KENYA - Nairobi and Trier.
- 1.10 - District : Kirinyaga Trial Site 23.1: Kerugoya
Formula Cropping season Lengths of growing period (exceeded in 6 out of 10 years) m/1 medium to iong 155 - 174 days m/s medium to short 115 - 134 days i = intermediate rains (at least 5 decades more than 0.2 Eo); which means moisture conditions are above wilting point for most crops.
2.1.2 Relevant Meteorological Data for the Kerugoya Trial Site
In this Section a breakdown is given of the following climatic parameters: rainfall, potential evaporation and temperature.
Rainfall :
Rainfall data are obtained from the nearest long-term rainfall recording station: 09037031, Kerugoya Water Office (elevation: 1570 m), 1.2 km N of the Kerugoya Trial Site (elevation: 1480 m). The data are listed in Table 23.1.4. At the trial site rainfall amounts are similar. In 20 out of 30 years precipitation at Kerugoya is more than 840 mm during the agro-humid period of the first rains (see Map 23.0.1), and more than 420 mm during the second rains (see Map 23.0.2). The methods of rainfall data analysis are described in Chapter IV.2.2 of the main report.
Temperature and potential evaporation(Eo):
Temperature data are extrapolated from 09037050, Embu Provincial Agri- cultural Training College (elevation: 1430 m), 20 km E of the Trial Site (elevation: 1480 m). The temperature gradient in this area is on average 0.6°C per 100 m. Potential evaporation (Eo) is calculated using the PENMAN formula, modified by MC CULLOCH (1965). The input parameters employed - windrun, sunshine hours and relative humidity - are obtained from 09037202, Embu Agro-Meteorological Station (elevation: 1450 m), 20 km E of the trial site.
Temperature and evaporation data for the Kerugoya Site are given in Table 23.1.5 and 23.1.6, and the rainfall pattern and potential evaporation are shown in Figure 23.1.5.
For more detailed information on the methodology of climatic description see Chapter IV.2.2 of the main report.
- 1.11 - Table 23.1.4 : Data of the Nearest Long-Term Rainfall Station
Station No.: 09037031 Total years for calculation: 25 Kerugoya Water Offices First year included: 1961 Elevation: 1570 m Last year included: 1985
Average annual rainfall: 1541 mm
Rainfall surpassed in 20 out of 30 years (-66% Probability): 1st rains: 840 mm 2nd rains: 450 mm (mid Mar. - beg. of Sep.) (beg. of Oct. - end of Jan.)
Decades Arithmetic Average Number of Rainy -66% Probabi- Years and Mean Days with Rainfall lity of ex- anal- Month (mm) > = 1 mm > = 5 mm ceeding ... mm ized
1 JAN 9.9 1 .3 1 .2 0.6 25 2 10.2 1 . 1 1 .0 2.5 25 3 10.9 1 .9 1 .7 3.4 25 4 FEB 13.0 1 . 4 1 . 4 4.0 25 5 7.1 1.2 1.1 1 .5 25 6 15.6 1 .2 1 .2 2. 1 25 7 MAR 24. 4 2. 1 2.0 7. 1 25 8 24. 9 2.3 2.2 8.8 25 9 54.5 4.3 4. 2 31 .4 25 10 APR 90. 4 5.6 5.4 62.4 25 11 110.8 6.6 6.3 82. 9 25 1 2 1 56.3 6.4 6.4 119.3 25 13 MAY 130.8 6.8 6.6 81 .5 25 14 76.6 5.7 5. 5 50.7 25 15 64. 4 5.7 5.4 39.5 25 16 JUN 26.2 3.2 3.0 7.0 24 17 17.3 2.8 2.5 5.5 24 1 8 26.6 4.0 3.6 9.6 24 1 9 JUL 18.6 4. 1 4.0 6.7 25 20 16.6 4.7 4.3 12.4 25 21 24. 1 5.7 5. 1 17.4 25 22 AUG 27. 1 5.0 4.7 15.2 25 23 23.6 5.0 4.6 17.7 25 24 1 5.8 4.7 4. 1 8.4 25 2 5 SEP 1 7.8 3.4 3. 1 11.4 25 26 16.0 3. 1 2.8 8.3 25 27 17.5 2.3 2. 1 8.8 25 28 OCT 30.6 3.3 ' 3.1 1 5. 9 24 29 79.0 4.3 4. 1 44.0 24 30 113.7 5.9 5.8 71 .6 24 31 NOV 85.4 4.9 4.8 48.3 23 32 53.8 4.9 4.7 35.2 23 33 58.0 4.5 4. 2 36.9 23 34 DEC 29.3 3. 2 3. 1 17.5 24 35 27.9 2.6 2.5 18.2 24 36 16.6 2.0 1 .9 8.3 24
- 1.12 - District: Kirinyaga Trial Site 23.1: Kerugoya
Table 23.1.5: Temperature (°O
JAN. FEB. MAR. APR. MAY JUN.
Mean temp. 19.7 21.1 21.6 20.5 19.5 18.3 Mean max.temp. 26.1 29.0 27.6 25.5 23.7 22.5 Mean min.temp. 13.3 13.3 14.6 15.5 15.4 14.1
JUL. AUG. SEPT. OCT. NOV. DEC.
Mean temp. 16.9 17.0 18.5 19.7 19.1 19.3 Mean max.temp. 21.1 21.4 24.1 25.6 23.9 25.4 Mean min.temp. 12.8 12.7 13.0 13.9 14.3 13.3
annual mean: 19 2 mean max. : 24.7 mean min. : 13.8
Table 23.1.6: Potential Evaporation (Eo) in mm per Decade:
JAN. FEB. MAR. APR. MAY JUN.
1st decade 43 49 49 38 35 31 2nd decade 43 49 49 38 35 31 3rd decade 47 40 54 38 39 31 Total : 133 138 152 114 109 93
JUL. AUG. SEPT OCT. NOV. DEC.
1st decade 29 31 40 44 39 40 2nd decade 29 31 40 44 39 40 3rd decade 32 34 40 48 39 45 Total : 90 96 120 136 117 125
average annual potential evaporation: 1423 mm.
For all the climatic data published in this Section, a data bank has been established by FURP on Personal Computers at the National Agricultural Laboratories in Nairobi.
- 1.13 - Figure 23.1.5: Rainfall and Potential Evaporation
200 -, (mm) 190 - Rainfall Station: 09037031 Kerugoya Water Office 180 - 170 - Meteorological Station: 160 - R 09037202 Embu Agromet. St. 150 - 140 - 130''- 120 - 110 - 100 - 90 - 80 - 70 - 60 - 50 - 40 - 30 - 20 - 10 - 0 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC District : Kirinyaga Trial Site 23.1: Kerugoya
2.1.3 Crop Suitability from the Climatic Point of View
A summary of the agro-climatic suitability of the most important seasonal crops is given in Table 23.1.7 below. Additional information on other crops, considered suitable from the agro-climatic viewpoint is given in the Farm Management Handbook, Vol. II/B, Central Kenya 1) .
Table 23.1.7: Agro-Climatological Crop List for Kerugoya
Crop/variety Av.No.of Altitudes2) Requirem.of Yield (or place of days to according well distri- potential ace. breeding) physiol. to growing buted rain- to water avai- e = early maturity period fall 3) in lability ") m = medium (m.) grow.period a = 1st rains 1 = late (mm. ) b = 2nd rains
Sunflowers 120-135 0 - 1800 350-650 a) very good HS 301 A b) good
Maize/m.mat. 140-170 1000-1700 500-750 a) good like H 512 b) fair
Maize/e.mat. Katumani 85-110 700-1600 260-500 b) good
Beans/e.mat a) good like GLP 2 80-100 700-1800 250-450 b) good to =Rose Coco very good
Potatoes/ 140-170 1800-2900 450-750 a) good m.mat. b) fair
1) R. JÄTZOLD and H. SCHMIDT, eds. (1983): Farm Management Handbook of Kenya, Vol. II/B, Central Kenya - Nairobi and Trier.
2) Most suitable altitudes; the length of the growing period increases with altitude; growth is also possible beyond the indicated altitude range, as long as the ecological limits have not been reached.
3) Lower figure for fair results, higher for very good results with some corrections due to rainfall distribution, evaporation and run-off losses.
4) Estimated yield potential: very good >80%, good = 60-80%, fair = 40-60% and poor <40% of the expected yield under optimum water availability adapted from R. JÄTZOLD and H. SCHMIDT, eds. (1982): Farm Management Handbook of Kenya, Vol. II/A, West Kenya.
- 1.15 - District : Kirinyaga Trial Site 23.1: Kerugoya
For the most important food crops in the area around the Kerugoya Trial Site, the crop coefficients (kc) are shown in Table 23.1.8, differentiated according to decades (10 day periods) of the growing season which is the time between planting or sowing and the physiological maturity. Furthermore, four crop development stages are distinguished in Table 23.1.8.
The crop coefficients for the climatic conditions at the Kerugoya Trial Site were estimated on the basis of data obtained from DOORENBOS and PRUITT (1977)1) and DOORENBOS and KASSAM (1979)7).
The data on the duration of each of the growing seasons and on the various development stages of each crop were assessed on the basis of local observations made under average climatic conditions.
The crop coefficients estimated for the various decades of the growing seasons were used to estimate the maximum (potential) evapotranspiration (ETm) under the prevailing climate, assuming that water was not a limiting factor for plant growth. For this calculation the following approximative formula was employed:
ETm = kc * Eo whereby: ETm= maximum (potential) evapotranspiration kc = crop coefficient Eo = potential evaporation (climatic evaporative demand)
In Figures 23.1.6a and 23.1.6b, the ETm-values are used to indicate the estimated maximum water requirements of the maize crops for optimum growth. Furthermore, the rainfall data at 66% reliability are shown in Figures 23.1.6a and 23.1.6b to give an indication of the water availability. However, when reading these figures, it must be borne in mind that the actual availability of water for the plants also depends, to a large degree, on. factors such as the run-off, the moisture storage capacity of the soil, the deep percolation of water etc.
The placement of the growing seasons of the various crops on the time axis as presented in Figures 23.1.6a and 23.1.6b was mainly based on the pattern of rainfall, whereby the peak water requirements of the plants should be met by high, reliable rainfall.
Detailed information on the calculation procedures and references are given in Chapter IV.2.2 of the main report. The interpretation of the diagrams mentioned above follows in Section 4 of this Volume (Conclusions from the Analyses of Climate and Soils).
1) FAO (1977): Crop Water Requirements - (= Irrigation and Drainage Paper, 24), Rome
2) FAO (1979): Yield Response to Water - (= Irrigation and Drainage Paper, 33), Rome
- 1.16 - Table 23.1.8 : Crop developient stages 1) and crop coefficients (Kc) 2) for approx. laxiiua (potential) crop evapotranspiration of the lost important seasonal crops grown at Kerugoya (site no. 23.1)
Crop/ Huiber of decades froi seeding resp. planting to (physiological) laturity Variety 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
MAIZE 0.7 0.75 0.8 0.83 0.89 0.96 1.01 1.05 1.05 1.05 1.05 1.05 1.05 0.9 0.79 0.63 HS 12 I I I II II II II III III III III III III IV IV IV NAIZE 0.6 0.7 0.76 0.87 0.99 1.05 1.05 1.05 0.9 0.66 KATUMANI I I II II II III III III IV IV
BEANS 0.7 0.75 0.8 0.89 0.99 1.05 1.05 1.05 0.82 0.49 Rose coco I I II II II III III III IV IV
POTATOES 0.7 0.75 0.8 0.84 0.92 1.0 1.05 1.05 1.05 1.05 0.98 0.87 0.76 I I I II II II III III III III IV IV IV
SUNFLOWER 0.7 0.75 0.79 0.88 0.97 1.05 1.1 1.1 1.1 1.1 1.1 0.92 0.52 HS 301 A I I II II II II III III III III III IV IV
1) Crop developient stages as defined in chapter IV 2.2 (lain report) I ; initial stage II = developaent stage III - lid season IV = late season 2) Kc = crop coefficient as defined in chapter IV 2.2 (lain report) Figure 23.1.6a: Water requirements Rainfall Station: 09037031 and availability for crop Kerugoya Water 0. Maize H 512, first rains
120-1 Trial Site 23.1 Kerugoya
mm 100-
80-
60- 00 I ETm 40-
20-
Decade 10 11 12 13 14 15 16 17 18 19 20 21 22 ' 23 MAR APR MAY JUN JUL AUG Figure 23.1.66: Water requirements Rainfall Station: 09037031 and availability for crop Kerugoya Water Office Maize/Katumani C. B., second rains
80 i Trial Site 23.1 Kerugoya
70- mm
ETm
I
36 DEC JAN District : Kirinyaga Trial Site 23.1: Kerugoya
2.2 Proposal for the Monitoring of Agro-Climatic Conditions in Phase II
For Phase II the agro-climatic recording programme should include:
fall records:
A rain gauge has to be installed at the Kerugoya Trial Site to measure the actual precipitation on the spot. Subsequently, data can be compared with both rainfall for a particular year and the long-term average of the nearest long-term rainfall recording station of the Meteorological Depart- ment: 09037031, Kerugoya Water Office (elevation: 1570 m), 1.2 km N of the Kerugoya Trial Site (elevation: 1480 m). It is recommended that the rain gauge at the Kerugoya Water Office be moved to another spot within the compound, as it is situated too close to a large tree.
2) Records on other relevant meteorological parameters:
Data on temperature, windrun, sunshine hours and relative humidity have to be obtained from 09037202, Embu Agro-Meteorological Station (elevation: 1510 m), 20 km E of the Kerugoya Trial Site, in order to calculate Eo (climatic evaporative demand).
For this purpose, a computerized PENMAN formula, modified by MC CULLOCH (1965) is available on PC.
3) Phenological records :
Dates of planting or sowing of each crop, emergence, start of tasselling (for maize crop), budding (for bean crop), flowering, ripeness or physiological maturity and harvest have to be recorded. Additionally the leaf area index (LAI) has to be determined every week (at least for the cereal crops) in order to provide a sound basis for water balance calculations. Other important features should also be recorded, above all rolling and wilting leaves, which indicate water stress and wilting point respectively before physiological maturity has been reached.
For these phenological observations a methodological guideline has to be distributed to the recording technical assistant.
Moreover, soil moisture checks and observations on rooting depth at the above-mentioned growing stages and run-off measurements would be needed to estimate the actual evapotranspiration of the various crops correctly.
For most of the data to be recorded, official forms from the Meteorological Department are available.
Detailed information on calculation procedures, as proposed for the monitoring of agro-climatic conditions, is given in Chapter IV.2.2 of the main report.
- 1.20 - District: Kirinyaga Trial Site 23.1: Kerugoya
3. Soils
In this Section, survey and laboratory data concerning the trial site and, more specifically, the soil profile are given. The evaluation of these data is shown in Sub-Section 3.3.
3.1 Survey Data
3.1.1 Brief Soil Description and General Information on the Soil
The brief description of the soils of the trial plot is followed by a rating of relevant soil-related land factors. The classes for these factors have been adapted from Andriesse and van der Pouw (1985), and a key for them is to be found in Chapter IV.2.3 of the main report.
Brief soil description
The soils are extremely deep, reddish brown to dusky red in colour, and consist of friable clay, with an acid humic topsoil. The prevailing soil structure is moderate, angular blocky. Soil bioporosity is high throughout.
Ratins of soil-related land factors
- Parent rock 1 rich: basic igneous rocks 2 moderately rich 3 poor
- Drainage 1 (somewhat) excessively drained 2 well drained 3 moderately well drained 4 imperfectly drained 5 (very) poorly drained
- Effective soil depth 1 extremely deep 2 very deep 3 deep 4 moderately deep 5 shallow 6 very shallow
- Inherent fertility 1 high 2 moderate 3 poor 4 very poor
- Topsoil properties 0 non-humic 1 humic 2 thick humic la acid humic 2a thick acid humic
- 1.21 - District: Kirinyaga Trial Site 23.1: Kerugoya
- Salinity 0 non-saline 1 slightly saline 2 saline
- Sodicity 0 non-sodic 1 slightly sodic 2 sodic
- Stoniness 0 non-stony 1 slightly stony 2 stony 3 very stony
- Rockiness 0 non-rocky 1 slightly rocky 2 rocky 3 very rocky
- Consistency (moist) 1 half-ripe 2 loose 3 very friable 4 friable 5 firm 6 very firm
- Moisture storage capacity 1 very high 2 high 3 moderate 4 low
- Excess surface water 0 none 1 occasional 2 seasonal 3 permanent
3.1.2 Detailed Profile Description and Spil Classification
Detailed information on the various soil properties as they occur in the different horizons is given in Table 23.1.9. The location of the profile near the trial plot is shown in Figure 23.1.7.
The soil profile is classified according to two systems, which are explained in Chapter II.2.3 of the main report.
1. Legend to the Soil Map of the World (FAO-Unesco, 1974), with adjustments according to the Kenya Concept (Siderius and van der Pouw, 1980): humic Nitisol.
2. USDA Soil Taxonomy (Soil Survey Staff, 1975): typic Paleudult. very fine-clayey family.
- 1.22 - Table 23.1.9: Detailed Profile Description of Trial Plot Kerugoya
'Profile nuaber: 23.1 Date of exaaination: 20-6-1986 Authors: Gachene/Kibe Saaple Colour ! Kottling ! Texture ! Cutans Structure jBiopores [ConsistencelConcretions Other No. o r l z o n (Hoist) Features Genetic J Depth \ Boundary I weak to nany v.f. 23.1.1 Ah 0- 25 5 YR 3/2 nil clay nil aoderate «any f. friable; nil dark redd, fine coaaon a. si.sticky- clear brown subang. bl, coaaon c. si, plastic smooth broken noderate aany v.f. 23.1.2 25 - 55 5 YE 4/3 nil clay thin aediua aany f. friable; nil reddish clay angular conaon a. sticky- clear brown blocky coiuon c. plastic soooth continuous aoderate Dany v.f. 23.1.3 Bwl 55-85 10 R 3/3 nil clay Doderately nediua aany f, friable; nil dusky red thick angular sticky- gradual clay blocky conoon a. plastic snooth coanon c. CO continuous aoderate lany v.f. I 23.1.4 B»2 85 - 135 10 R 3/3 nil clay noderately aediua nany f. friable; nil dusky red thick subangular coaaon a. sticky- clay blocky coaaon c. plastic
23.1.5 Ah (control saaple)
Reaarks: Profile was aoist throughout at the tine of description and sanpling. Colour: redd. = reddish Structure: subang. bl. : subangular blocky Biopores: v.f. - verv fine; f. = fine; a. - aediua; c. = coarse Consistence: si. = slightly an do (?) - luvic PHAEOZEH Field pH was not determined. District: Kirinyaga Trial Site 23.1: Kerngoya
3.1.3 Soil Sampling
Soil samples (profile, composite, farmers' fields, pF rings) are listed in Sub-Section 3.2. Figure 23.1.7 shows the location of the composite sampling Blocks (I to IV) as well as the location of the profile pit.
p*profile pit
Figure 23.1.7: Location of Composite Sampling Blocks and Profile Pit at the Kerugoya Trial Plot
3.2 Laboratory Data
The soil samples from the profile and the composite samples from the various blocks of the main trial site and from the farmers' fields were analyzed in the laboratory. The results are compiled in Tables 23.1.10 to 23.1.12. The methodology applied for obtaining these results is described in detail in Chapter IV.2 of the main report.
- 1.24 - District: Kirinyaga Trial Site: 23.1 Kerugoya
Table 23.1.10 : Analytical Results (physical and chemical analysis, results on air dry soil basis) Profile Samples from Trial Site
Horizon Depth Field Lab. ) 2 mm. Sand Silt Clay Texture PH PH Diff. Cond. cm. No. No. % % X X Class KC1 H2O PH H2O
1 Ah 0-25 23.1.1 5974/86 — 14 22 64 C 5.0 5.6 0.6 0.07 2 BA 25-55 23.1.2 5975 — 14 20 66 C 5.1 5.8 0.7 0.05 3 Bw1 55-85 23.1.3 5976 — 16 30 54 C 5.1 5.8 0.7 0.04 4 Bw2 85-135 23.1.4 5977 — 16 16 68 C 5.1 5.9 0.8 0.04 r Ü 6 Ah Control 23.1.5 5978 —— 18 20 62 C 5.1 5.8 0.7 0.06 7 8
Saturation Extract Na K Hg Ca Hn ECEC Bases Al Al H+Al 4/iTII— . X Mater PH El.Cond. nnc./ lUUyfD. X X me./IOOgm. KC1 1 NA NA NA 0.06 0.22 3.30 4.80 1.03 11.10 75.50 1.26 0.14 0.38 2 NA NA NA 0.08 0.06 2.90 5.20 0.74 11.10 74.23 1.98 0.22 0.50 3 NA NA NA 0.14 0.36 4 NA NA NA 0.12 0.32 r u 6 NA NA NA 0.12 0.36 7 8
105 deg.C Na K Hg Ca CEC pH8.2 Bases Bases+Al Al Org. C N C/N P Olsen in rel.to me./100gm. Acetati - X me./lOOgm. X X X ppm. air dry
1 0.06 0.18 0.90 2.50 22.60 16.11 3.78 3.70 2.94 0.34 8.6 0.91 2 0.07 0.06 1.10 4.40 21.70 25.94 5.85 3.76 1.77 0.19 9.1 0.90 3 0.06 0.05 0.90 4.00 22.60 22.17 5.15 2.72 0.70 0.13 5.6 0.88 4 0.08 0.03 1.00 2.00 19.10 16.28 3.23 3.72 0.30 0.05 6.0 0.89 3c 6 0.08 0.10 1.30 3.70 24.40 21.23 5.30 2.26 0.90 7 8
Moisture Retention Capacity Horizon Depth Voi.X Moisture Avail. Moisture Bulk Dens cm. bar 0 1/10 1/3 5 15 Capacity kg./l. pFO 2 2.5 3.7 4.2 mm./10cm. 105 deg.C
1 Ah 20-25 53.3 42.7 38.5 29.8 27.5 13.0 1.20 2 BA 50-55 57.0 45.9 42.5 28.8 26.9 19.0 1.05 3 4
NA : not applicable me./IOOgm. = milliequivalents per 100 gm. of soil AgTU : Silver Thio Urea Extraction Acetate = Bases by Ammonium Acetate pH 7, CEC by Sodium Acetate pH 8.2 pH and conductivity in suspension 1:2.5 v/v
- 1 .25 - District: Kirinyaga Trial Site: 23.1 Kerugoya
Table 23.1.11 : Analytical Results (chemical analysis, results on air dry soil basis) Trial Site Composite Samples
Depth Block number X S Max. ! cm. I II III IV V VI VII diff. ! j ! Lab. Ko. /86 20 5883 5885 5887 5889 ! 2 50 5884 5886 5888 5890
! 4 Fine earth X 20 100 .100 100 100 100 0.00 o.oo ; ! 5 50 100 100 100 100 100 0.00 o.oo ; ! 6 Vol.»eight kg./l. 20 0.91 0.99 1.04 1.00 0.99 0.05 0.13 ; ! 7 50 1.04 1.04 1.05 1.01 1.04 0.02 0.04 ! ! 8 105 deg.C / air dry 20 0.89 0.92 0.92 0.92 0.91 0.01 0.03 ! : 9 50 0.91 0.91 0.92 0.91 0.91 0.00 0.01 ! ! io 1 11 pH H20 1/1 20 5.2 5.6 5.9 5.9 5.65 0.33 0.70 ! cx i 50 5.6 5.7 5.8 5.8 5.73 0.10 0.20 ! ! 13 pH H2O 1/2.5 20 5.8 6.3 6.5 6.0 6.15 0.31 0.70 ! ! 14 50 6.2 6.4 6.2 6.0 6.20 0.16 0.40 ! ! 15 pH N KC1 1/2.5 20 4.7 4.8 4.8 4.7 4.75 0.06 0.10 ! ! 16 50 4.7 4.9 4.5 4.4 4.63 0,22 0.50 ! ! 17 ! 18 C org. X 20 t. 79 1.30 1.23 1.45 1.44 0.25 0.56 ! i 19 N tot. X 20 0.14 0.16 0.15 0.14 0.15 0.01 0.02 i ! 20 C/H 20 13 8 8 10 9.87 2.20 4.66 ! ! 21 ; 22 Mod.Olsen Abs. 260nm 20 96 96 84 95 92.75 5.85 12.00 ! ! 23 (1/1000) 50 53 63 60 62 59.50 4.51 10.00 : ! 24 ! 25 S04 soluble ppm. 20 43 ! 26 50 9 i o? i t' : 28 P Men. 1/5 ppm. 20 76.00 128.00 52.00 86.00 85.50 31.72 76.00 ; 29 50- 34.00 42.00 39.00 42.00 39.25 3.77 8.00 ; ! 30 P Olsen ppm. 20 40 ! 31 50 12 ! 32 P mod.Olsen ppm. 20 80.00 42.50 69.00 86.00 69.38 19.25 43.50 ! ! 33 50 30.00 41.00 45.00 52.00 42.00 9.20 22.00 ! ! 34 P Citric ac. ppm. 20 94 ! 35 50 33 I 36 ! 37 ECEC AgTU me./100gm. 20 11.10 11.20 ! 38 Bases X 20 75.77 72.68 ! 39 A1X 20 5.41 3.04 ! 40 ! 41 Hp BaC12 me./lOOgm. 20 0.60 ! 42 50 I 43 H S Al KC1 me./IOOgm 20 0.92 0.46 0.32 0.70 0.60 0.26 0.60 i ! 44 50 0.48 0.42 0.36 0.85 0.53 0.22 0.49 1 ! 45 Al 3- KC1 me./100gm. 20 0.60 0.34 0.16 0.32 0.36 0.18 0.44 ! ! 46 50 0.34 0.22 0.18 0.56 0.33 0.17 0.38 ! ! 47 Al 3- AgTU me./100gm 20
! 49 Sat.Ext. X H20 20 not applicable ; so 50 not applicable ! 51 Sat.Ext. El.Cond. 20 not applicable ! 52 50 not applicable ! 53 Sat.Ext. pH 20 not applicable ! 54 50 not applicable ! 55
- 1 .26 - contd. District: Kirinyaga Trial Site: 23.1 Kerugoya Table 23.1.11 : Analytical Results (chemical analysis, results on air dry soil basis) Trial Site Composite Samples Depth Block number x s Max. ! cm. I II III IV V VI VII diff. ! ; , Lab. No. /86 20 5883 5885 5887 5889 ! ! 2 50 5884 5886 5888 5890 1 56 HaMeh.1/5me./100gm 20 0.08 0.08 0.08 0.08 0.08 0.00 o.oo ! 1 57 50 0.08 0.11 0.11 0.08 0.10 0.02 0.03 I ! 58 Na Ag-TU me./IOOgm. 20 0.06 0.05 1 CQ ! 60 K Heh.1/5 rrte./IOOgrn. 20 0.36 0.11 0.08 0.04 0.15 0.14 0.32 ', ; 6i 50 0.08 0.04 0.08 0.04 0.06 0.02 0.04 1 ; 62 K mod.01. me./IOOgm. 20 0.60 0.37 0.10 0.10 0.29. 0.24 0.50 1 ; 63 50 0.13 0.10 0.08 0.08 0.10 0.02 0.05 1 ! 64 K Ag-TU me./IOOgm. 20 0.65 0.49 ; 65 ; 66 Mg Meh.1/5 me./IOOgm 20 0.80 3.60 5.10 4.10 3.40 1.84 4.30 1 1 67 50 4.50 4.30 4.90 4.30 4.50 0.28 0.60 1 ; 68 Hg mod.01. me./IOOgm 20 3.20 3.26 3.45 1.98 2.97 0.67 1.47 1 ; 69 50 1.89 1.47 1.23' 1.47 1.52 0.28 0.66 ! 1 70 Hg Ag-TU me./IOOgm. 20 2.60 2.40 ! 71 1 CN J Ca Heh.1/5 me./IOOgm 20 Trace 2.80 3.60 1.60 2.00 1.57 3.60 1 ! 73 50 2.80 2.40 2.00 1.20 2.10 0.68 1.60 1 1 74 Ca mod.01. me./IOOgm 20 6.00 6.00 8.00 5.00 6.25 1.26 3.00 1 ! 75 50 6.00 7.00 6.00 2.00 5.25 2.22 5.00 ! 1 76 Ca Ag-TU me./IOOgm. 20 5.10 5.20 ! 77 1 78 Mn Heh.1/5 me./IOOgm 20 0.30 0.43 0.50 0.40 0.41 0.08 0.20 1 ; 79 50 0.50 0.58 0.52 0.48 0.52 0.04 0.10 ! ! 80 Hn mod.01. me./IOOgm 20 0.07 0.04 0.04 0.06 0.05 0.02 0.04 ! ! 81 50 0.04 0.02 0.04 0.04 0.03 0.01 0.02 1 l 82 Hn Ag-TU me./IOOgm. 20 1.24 1.67 l 83 ! 84 Zn HC1 ppm. 20 3.70 ! 85 50 4.25 ! 86 Zn mod. 01. ppm. 20 11.00 14.00 16.00 9.00 12.50 3.11 7.00 1 l 87 50 18.00 15.00 15.00 7.00 13.75 4.72 11.00 1 1 OÛ 1 00 ! 89 Cu HC1 ppm. 20 0.80 1 90 50 0.80 1 91 Cu nod. 01. ppm. 20 7.00 6.00 6.00 4.00 5.75 1.26 3.00 1 1 92 50 7.00 6.00 6.00 4.00 5.75 1.26 3.00 ', 1 93 ! 94 Fe HC1 ppm. 20 13.00 1 95 50 22.00 1 96 Fe mod. 01. ppm. 20 265 210 185 185 211.25 37.72 80.00 ! 1 97 50 230 220 215 200 216.25 12.50 30.00 1 i qg i 90 1 99 FeOxalate X 20 1.10 ; loo 50 1.27 1101 Al Oxalate % 20 1.45 1102 50 1.35 NA : not applicable me./IOOgm. - nilliequivalents per 100 Ji. of soil Meh. : Mehl ich Analysis mod. 01. : Modified Olsen Extraction AgTU : Silver Thio Urea Extraction - 1.27 - District: Kirinyaga Trial Site: 23.1 Kerugoya
Table 23.1.12 : Analytical Results (chemical analysis, results on air dry soil basis) Farmers' Fields Composite Samples
Depth Farmers fields (code) Trial site X S Hax. cm. A B C D E F G H J average diff.
; , |Lab. No. 20 5891 5892 5893 5894 5895 5896 5897 5898 5899 ! 2 [Fine earth % 20 100 100 100 100 100 100 100 100 100 100 100 0.00 0.00 ! 3 I Vol,weight kg./l. 20 1.02 0.97 1.01 0.98 1.02 1,03 0.98 1.00 1.00 0.99 1.00 0.02 0.06 ! 4 |105 deg. C / air dry 20 0.91 0.91 0.92 0.92 0.92 0.91 0.91 0.92 0.92 0.91 0.92 0.01 0.01 1 c 1 I 3 ! 6 |pH H2O 1/1 20 5.80 5.90 6.00 6.10 6.00 6.00 6.00 6.10 5.60 5.65 5.92 0.18 0.50 ; 7 |pH H2O 1/2.5 20 6.20 6.50 6.90 6.30 6.40 6.60 6.30 6.50 5.10 6.15 6.30 0.47 1.80 ! 8 |pH N KC1 1/2.5 20 4.70 5.30 5.20 4.90 4.80 5.10 4.80 4.80 4.00 4.75 4.84 0.36 1.30 1 a 1 i ' ! 10 IC org. % 20 1.03 1.04 1.07 0.99 0.95 0.86 1.47 0.97 0.90 1.44 1.07 0.21 0.61 ! il |N tot. % 20 0.11 0.32 0.24 0.25 0.08 0.13 0.32 0.22 0.16 0.15 0.20 0.08 0.24 ! 12 IC/N 20 9 3 4 4 12 7 5 4 6 10 6.40 2.95 8.63 i 'à 1 ! 14 |Hod.Olsen Abs.260nm. 20 66 84 60 61 84 73 85 74 70 93 74.98 11.10 32.75 1 1 i 'm3 ! 16 !P Heh. 1/5 ppm. 20 70 60 96 49 70 30 149 89 20 86 71.85 36.70 129.00 ! 17 |P mod.Olsen ppm. 20 48 53 98 68 53 20 94 91 32 69 62.54 26.36 78.00 1 ! 19 |Na Heh.1/5 me./100gm. 20 0.08 0.11 0.11 0.11 0.04 0.08 0.22 0.11 0.11 0.88 0.19 0.25 0.84 | 20 1 ! 21 |K Heh.1/5 me./100gm. 20 0.14 0.26 0.46 0.90 0.11 0.08 0.76 0.14 0.11 0.15 0.31 0.30 0.82 ; 22 !K mod.Ol. me./IOOgm. 20 0.26 0.35 0.73 1.30 0.15 0.13 1.28 0.18 0.10 0.29 0.48 0.47 1.20 1 ! 24 [Hg Heh.1/5 me./IOOgm. 20 3.20 3.60 4.00 4.00 4.50 4.90 4.50 3.00 4.80 3.40 3.99 0.68 1.90 ! 25 jHg mod.Ol. me./1G0gm. 20 3.15 2.91 2.83 3.95 4.14 4.78 2.23 3.05 4.29 2.97 3.43 0.81 2.55 1 ! 26 1 ! 27 |Ca Heh.1/5 me./IOOgm. 20 3.20 3.60 7.60 4.80 2.00 1.60 12.40 4.40 2.80 2.00 4.44 3.31 10.80 ! 28 |Ca mod.Ol. me./100gm. 20 8.00 8.00 13.00 10.00 7.00 6.00 17.00 10.00 6.00 6.25 9.13 3.55 11.00 29 1 30 ,'Hn Heh.1/5 me./100gm. 20 0.55 0.50 0.36 0.46 0.52 0,48 0.20 0.43 0.76 0.41 0.47 0.14 0.56 31 jMn mod.Ol. me./100gm. 20 0.07 0.09 0.15 0.10 0.09 0.07 0.04 0.08 0.06 0.05 0.08 0.03 0.11 15 1 1 , 1 33 |Zn mod.Ol. ppm. 20 12.00 16.00 13.00 19.00 13.00 13.00 21.00 16.00 10.00 12.50 14.55 3.40 11.00 1 34 1 35 |Cu mod.Ol. ppm. 20 5.00 8.00 6.00 17.00 6.00 6.00 6.00 7.00 6.00 5.75 7.28 3.51 12.00 1 36 1 37 |Fe mod.Ol. ppm. 20 215 210 195 200 200 200 135 230 175 211 197.13 26.13 95.00 1 38 1 39 ;Hp BaC12 me./IOOgm. 20 40 ;H J Al fXI me./100gm. 20 0.44 0.38 0.28 0.36 0.38 0.36 0.36 0.44 0.32 0.60 0.39 0.09 0.32 41 |A1 KC1 me./100gm. 20 0.30 0.24 0.08 0.18 0.16 0.18 0.14 0.18 0.12 0.36 0.19 0.08 0.28 NA : not applicable me./IOOgm. : ni 11(équivalents per 100 gm. of soil ppm. : parts per million Heh. : Hehlich Analysis Hod. 01. : Hodified Olsen Extraction
- 1.28 - District: Kirinyaga Trial Site 23.1: Kerugoya
3.3 Evaluation of Soil Data
3.3.1 Literature References and Soil Correlation
Since 1972 the Kenya Soil Survey has carried out many soil surveys and site evaluations and, in addition, some surveys were conducted by other agencies. A complete list of soil survey reports is given in Chapter II.2 of the main report. A report referring to the area in which the trial site is situated is listed below.
Literature references:
W.G. Sombroek , H.M.H. Braun and B.J.A. van der Pouw El (1982). Exploratory Soil Map and Agro-Climatic Zone Map of Kenya, 1980, scale 1:1,000,000.
In order to correlate existing information with findings at the trial site, the map units and classification units in the above-mentioned reports have been grouped in Table 23.1.13. Moreover, the FURP soil map unit (Map 23.0.4) and the classification of the soil of the profile at the trial plot are given.
Table 23.1.13: Soil Correlation with Respect to the Kerugoya Trial Site
Reference Map unit Soil Classification
El R2 humic Nitisols
FURP RB2 humic Nitisols
Trial plot profile humic NITISOL
The only source for the area around Kerugoya is El. It indicates humic Nitisols for this area, and this was confirmed at the trial site, although the clay increase is not high enough to key out as such. It is assumed, however, that this is due to an analytical laboratory error.
3.3.2 Representativeness
For two reasons, statements about the representativeness of the soils of the trial site should be made with care. Firstly, soil' classification units are mainly based on properties of a relatively permanent nature, i.e. those of the subsurface horizons and not those of the topsoil.
Secondly, the generally high variability of topsoil properties within short distances is not reflected in relatively small-scale reconnaissance soil maps (1:100,000 to 1:1,000,000). In this report, soils of a map unit
- 1.29 - District: Kirinyaga Trial Site 23.1: Kerugoya
considered to be within the "area of representativeness" must meet the following requirements :
(a) the soil-related land factors must have the same or similar ratings ;
(b) soil classification must be the same or similar.
The extent to which all the FURP trial sites are representative of the soils of Kirinyaga District is shown in Map 23.0.5: "Groupings of Soil Mapping Units Represented by Trial Sites in Kirinyaga District". This map is discussed in Sub-Section 23.0.5. Distinction is made between high representativeness - code A - and moderate representativeness - code B if soil conditions are slightly more favourable than at the trial site and code B- if soil conditions are slightly less favourable than at the trial site. Code C is applied for the remaining parts of the District, where none of the FURP trial sites are representative.
Within Kirinyaga District, the Kerugoya Trial Site has high representa- tiveness (Grouping 23.1.A) for the humic Nitisols of soil map unit RB2, which includes Kianyaga, Kerugoya and Baricho.
The Kerugoya Trial Site is also representative of areas outside Kirinyaga District, but the groupings are not indicated as such, since Trial Sites 20.1 (Githunguri, Kiambu District), 21.1 (Kareti, Muranga District), 24.3 (Embu A.R.S., Embu District), and 25.1 (Kaguru F.T.C., Meru District) also represent soil map unit RB2 in the respective Districts. For neighbouring Nyeri District, Grouping 21.1.A is given for soil map unit RB2. Grouping 23.1.A might also be valid for parts of this area.
Out of the five humic Nitisols in Central and Eastern Province, the Kerugoya site has by far the lowest organic matter content, both for the main plot and for the farmers' fields.
3.3.3 Variability of Soil Properties within the Trial Site
Trial Site 23.1 has a uniformly extremely deep soil with an acid humic topsoil. In spite of the relatively low organic matter content, the maize crop in June 1986 was observed to be doing very well. A comprehensive listing of soil test values is given in Tables 23.1.10 to 23.1.12. In this Sub-Section, a breakdown is given on the pH and organic carbon content of the-upper 20 cm. of the soils of the trial site.
The data for the profile pit differ considerably from those for the composite samples. Among the farmers' fields, the differences are relatively slight. pH-H2O: profile pit: 5.0 composite samples: 4.7 - 4.8 farmers' fields: 4.0 (field I) 4.7 - 4.9 (fields A,D,E,G,H) 5.1 - 5.3 (fields B,C,F)
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organic carbon content : profile pit: 2.9% (?) composite samples: 1.2% (Block III) - 1.8% (Block I) farmers' fields: 0.9% - 1.1% (all fields except G) 1.5% (field G)
3.3.4 Fertility Status of the Soil
The criteria applied for the interpretation of the analytical data are outlined in Chapter IV.2 of the main report.
3.3.4.1 Soil Profile
The analytical data of the soil samples taken from the profile pit, situated at the outer edge of the trial site and close to Block I (see figure 23.1.7) are presented in Table 23.1.10 and are interpreted in the following paragraphs.
There is no presence of physical obstacles or extreme acidity in the subsoil which would limit the rooting depth of the soil. The capacity for plant available moisture in the upper 100 cm. of the profile may roughly be estimated from the pF analysis carried out on the Ah and BA horizons, and it probably exceeds 150 mm. As the roots may exploit a considerably deeper soil volume, the available moisture capacity in the effective soil depth is very high (>160 mm.).
All horizons down to a depth of 135 cm. (maximum sampling depth) have a fairly constant and moderate to high CEC (pH 8.2) of 19 to 23 me./100 gm. The base saturation is low (16 %) in the Ah horizon, low to moderate (26 % and 22 %, respectively) in the BA and Bwl horizons, and low in the Bw2. However, the base saturation of the topsoil (Ah and BA horizons) would be moderate (37 % and 38 % respectively) when calculated with the sum of bases by Silver-Thiourea. This would be more in line with the slightly to mode- rately acid soil reaction.
The K saturation of the exchange complex is low (<0.2 me./100 gm.) in the Ah horizon and very low (<0.06 me./100 gm.) in all underlying horizons. This low K status contrasts with the high K found in the topsoil of the adjacent Block I; however, it appears in line with the K status of the other blocks.
The two extraction methods used produced contradictory results for exchangeable Mg and Ca. The values by Ammonium-Acetäte are much lower than those by Silver-Thiourea. According to the first method, Mg is in the high range (0.9 - 1.3 me./100 gm.) and Ca is low (2 - 4.4 me./100 gm.), whereas the latter method shows extremely high Mg 2.9 - 3.3 me./100 gm.) and low to medium Ca values (4.8 - 5.2 me./100 gm.).
The soil reaction of the entire profile is slightly to moderately acid (pH KC1 5 - 5.1), which is favourable for the growth of most plants. Only very low amounts of Al are exchangeable (<0.22 me./ 100 gm. and <5 % of exchangeable bases plus Al), which may not affect even sensitive plants.. The trial site composite samples are slightly more acidic.
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The organic matter content of the topsoil is in the high range; the humus < content decreases continuously with depth from 2.9 % C in the Ah (very humic) to 0.3 % C in the Bw2 (poor in humus). Total N is high in the Ah and moderate in the BA horizon. The C/N ratio is about 9 in the topsoil, which is medium to wide. All composite soil samples show considerably lower C and N values (approximately 50%) than the profile.
3.3.4.2 Soil Fertility Assessment of Composite Samples
The analytical results for the composite samples from the trial site (depths 0-20 cm. and 20-50 cm.) are presented in Table 23.1.11, and those for the farmers' fields (depth 0-20 cm. only) are shown in Table 23.1.12.
The composite samples were analyzed to assess the chemical fertility status of the soil, with special emphasis on the availability of the important nutrient elements to the plants. The "available nutrients" were estimated by means of two complementary methods, the "Mehlich" diluted double-acid method (NAL routine) and a "modified Olsen" bicarbonate + EDTA extraction.
The interpretation of the presented analytical data is in so far tentative for both methods as the validity of the applied ratings (ranges for Low, Medium, High) has not yet been verified by field trials in the various regions of Kenya.
The trial site composite samples investigated are all slightly more acid than the profile and in the moderately acid range (pH KC1 4.4 - 4.9). The farmers' fields show erratic pH values ranging from strongly to slightly acid (pH KC1 4 - 5.3). Exchangeable acidity and particularly exchangeable Al are very low throughout.
The total N content of the moderately humic soils (0.9 - 1.8 % C) is moderate (0.14 % N) in the trial site composite samples and low to medium in the farmers' fields (0.05 - 0.13). The generally medium to wide C/N ra- tios and the other prevailing soil and climatic conditions indicate that the N availability is probably moderate in the trial site and low to moderate in the farmers' fields, changing with the humus content. The UV absorption of the modified Olsen extract indicates a low N supplying capa- city from both the topsoil and the subsoil, so that from the deep soils a low to moderate N supply may be expected.
Soluble S04 was determined in Block I of the trial site only. The reported values are very high (43 ppm. in the topsoil).
In the trial site composite samples, "available" P is erratic, but very high throughout. In the topsoil, the Mehlich-P varies between 52 ppm. and 128 ppm., the modified Olsen-P ranges from 42 ppm. to 86 ppm. In general, the farmers' fields show similarly high P values up to 150 ppm. (field G). The lowest P was found in fields F and J (moderate to high P status). The N supplying capacity is probably inadequate to the P availability as indicated by the C/P (mod. 01.) ratio. The ratios are on average 207 in the trial site and 177 in the farmers' fields, much narrower than the proposed upper limit of 400 for a good growing crop in a moderately humic soil.
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According to the Mehlich analysis, only the topsoil of Block I is medium in K (0.36 me./100 gm.)» whereas all other trial site composite samples show very low K values (0.04 - 0.11 me./100 gm.). K by the modified Olsen method is high in the topsoil of Block I (0.6 me./100 gm.), moderate in the topsoil of Block II (0.37 me./100 gm.), and low to very low in all other trial site composite samples (0.08 - 0.13 me./100 gm.). In the farmers' fields, the K availability varies in a wide range from very low to very high. Fields A, E, F, H and J are particularly low in K (0.08-0.26 me./100 gm.), while fields D and G are rich in K (0.8 - 1.3 me./100 gm.).
The "available" amounts o.f Mg are always far in the high range, while Ca is generally moderate, according to both the Mehlich analysis and the modified Olsen method. Ca is lower in Block IV than in the rest of the trial site. The Ca status of the farmers' fields varies in a wide range (1.6 - 12.4 me./TOO gm. by Mehlich analysis, 6-17 me./100 gm. by modified Olsen method); fields C and G show high Ca values. Similar to the exchangeable bases the cations are adequately balanced with respect to plant nutrition. However, the Ca/Mg ratio is narrow.
"Available" Mn is, according to the Mehlich analysis, well within the adequate range. In contrast, the modified Olsen method shows only low or even very low values (<0.2 me./TOO gm.).
According to the modified Olsen method, Zn and Cu are available in suffi- cient quantities in the trial site and in all farmers' fields. In contrast, the HC1 extractable Zn and Cu determined in Block I of the trial site are both below the critical levels.
Fe was extracted in moderate to high amounts from all samples by the modified Olsen method. The oxalate extraction for amorphous oxides and hydroxides yielded moderate quantities of Fe and Al (Block I only).
The evaluation of the Mehlich Analysis data according to NAL standards is given in Table 23.1.14.
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Table 23.1.14: Evaluation of the Mehlich Analysis Data According to NAL Standards
Parameter Trial Site Farmers' Fields
Soil reaction (pH) Moderately acid Moderate to slightly acid Acidity (Hp) Low Low
Available nutrients Sodium Low Low Potassium Low Low to adequate Calcium Adequate Adequate Magnesium Adequate Adequate Manganese Adequate Adequate Phosphorus Adequate Adequate
Total Nitrogen Low Low Organic Carbon Moderate Moderate
C / N Ratio Favourable Favourable Ca / Mg Ratio Not favourable Not favourable Ca / K Ratio Not favourable Not favourable K / Mg Ratio Not favourable Not favourable
Remarks on Trial Site : Soil reaction is favourable for most crops. Positive yield responses to K, N and manure applications are expected. Yield responses to P and lime applications are unlikely.
Remarks on Farmers' fields : Same as for trial site
3.4 Sampling Programme for Laboratory Analyses during Phase II
3.4.1 Soil Samples
Soil samples will be collected once a year at the beginning of the long rains in March just after ploughing and before the fields are planted. The samples will be taken individually from two depths (0 - 20 cm and 20 - 50 cm) for each replication of the selected fertilizer treatments, and only from the plots in Module 2 with maize/beans mixed cropping.
The treatments to be sampled are:
Trial I: N0:P0 N75:P75 N0:P75 N75:P0
Trial II with lime treatment : 0 FYM FYM+NP NP+K NP+lime FYM+lime FYM+NP+lime NP+K+lime
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Trial II, lime treatment replaced by K' (25 kg./ha. K20) : 0 FYM FYM+NP NP+K FYM+NP+K' NP+K+K'
Farmers' Fields C, G, and J are suggested
3.4.2 Plant Samples
Harvest samples from the maize/beans mixed crop include individual samples of grain and straw from maize and beans respectively. Samples will be collected separately from each replication of the treatments where soil samples were taken, i.e.:
Trial I: N0:P0 N75:P75 N0:P75 N75:P0
Trial II with lime treatment: 0 FYM FYM+NP NP+K NP+lime FYM+lime FYM+NP+lime NP+K+lime
Trial II, lime treatment replaced by K' (25 kg./ha. K20): 0 FYM FYM+NP NP+K FYM+NP+K' NP+K+K'
Farmers' fields: Harvest samples will only be collected from those farmers' fields where soil samples were taken. Individual samples of grain and straw will only be required from the maize crop.
3.4.3 Other Samples
From every batch of applied FYM three representative samples will be taken.
4. Conclusions from the Analyses of Climate and Soils
4.1 Moisture Availability
The amount of rainfall, which is surpassed in 20 out of 30 years (i.e. 66% probability), constitutes the basis for estimating moisture availability during the growing periods. Other parameters of the water balance such as moisture storage capacity, run-off, and deep percolation also have to be considered in order to obtain a comprehensive picture of the moisture availability.
For example, the water requirements and the water availability for maize H 512, first rains, at the Kerugoya Trial Site, can be interpreted as follows :
Figure 23.1.6a shows that the maximum water requirements (ETm) of the maize crop are not in line with the rainfall pattern at the 66% probability level, but on the prevailing deep soils, the surplus of water (peak in April) can to a large extent be stored.
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Run-off is considered to be moderate: the trial site is located on sloping land (4-6%) and the crop does not provide adequate ground cover at the time of maximum rainfall intensity in April and May. However, the soil has a very stable structure, preventing crusting or surface - sealing.
Deep percolation and lateral sub-surface flow could be estimated, but can be omitted, since they are generally very low, except during the period of high rainfall intensity in April/May, and to some extent in October/November.
Since the plot has a remarkably concave shape, lateral sub-surface flow and run-off mainly affect the upper parts. Here the "lost" water to a large extent flows as additional water (as run-on and sub-surface flow) to the lower block. For the Kerugoya Trial Site, the moisture storage capacity is rated very high (i.e. >160 mm.). Most of the water surplus of April and May can, therefore, be stored in the soil in order to offset the rainfall deficits likely to occur from June onwards.
Summarizing the evaluation of the climatic factors, the yield potential from the climatic point of view can, for the maize crop, first rains, be rated good on a "20 out of 30 year" basis. It must be stressed once more, however, that water availability conditions on the lower block should be considered as being more favourable. In the second rains, conditions are less favourable as shown in Figure 23.1.6b. Early maturing crops like Katumani maize are better adapted to the. pattern of reliable rainfall than the medium maturing varieties.
4.2 Nutrient Availability in Relation to Possible Fertilizer Requirement
The soil is characterised by a moderate humus content. The natural N supply from the soil is probably low to moderate. P availability appears high to very high. Plants probably cannot fully utilize the P resources because of the limited N availability. The K values change within short distances and range from very low to very high, even within the trial site. The prevailing moderately acid soil reaction is favourable for the growth of most crops.
Fertilizer applications should first of all involve N and K. P will be of secondary importance in many places.
For sustained high yields regular N fertilization will be necessary, either from FYM, green manure or in mineral form. When mineral N is applied regularly, it should be supplemented with mulch and other organic amendments. This is to protect the topsoil, particularly during the heavy rains in April/May, and to maintain its high humus content. Humus plays an essential role in stabilizing the structure of the topsoil and in prevent- ing applied nutrients from leaching too quickly.
According to the soil analytical data, K is probably a limiting factor in many fields, including Blocks III and IV of the trial site, and response to K alone may occasionally be obtained. In Block I and in farmers' fields D and G, K applications are not needed immediately. However, the analytical
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data give no estimate of the reserves of K beyond the exchangeable pool, but its limitations are indicated by the rather low K levels of the sub- soil. Therefore, even in fields which at present show a high K status, the amounts of K removed with the harvests should be replaced.
As K fertilizer, K2SO4 should generally be preferred to KCl (both contain 50% K20) as the S04-ion is an important plant nutrient and it enhances P availability. The form in which K is applied should also take into account crop requirements (e.g. KCl to cabbage, but not to Irish potatoes).
The soil analysis indicated a high to very high P availability in all samples, and hardly any responses to P fertilizer may be expected. When combined with high doses of N and K, P as TSP will probably show a positive effect on plants with a high P demand (e.g. potatoes) in farmers' fields F and J.
Under the prevailing soil conditions liming is not needed and the acidifying effects of the applied mineral or organic fertilizers will be sufficiently buffered by the soil for the duration of the trials over' five years. However, soil acidity and exchangeable Al should be monitored closely. Over longer periods of fertilizer use, the increasing soil acidity should be counterbalanced by liming. N-fertilizer has particularly high lime requirements, i.e. approximately 1.8 Kg. of CaCO3 per Kg. of applied N; in the case of CAN, which contains Ca, only about 0.8 Kg. CaCO3 per Kg. N or 0.2 Kg. lime per Kg. of CAN will be needed. TSP does not contribute sub- stantially to the Ca budget of the soil.
4.3 Other Relevant Land Qualities
In addition to an assessment of moisture and nutrient availability, the following land qualities are relevant in the context of fertilizer use: a) Oxygen availability. In general, the topsoils of humic Nitisols have good physical properties. High porosity and a stable structure maintain an environment in which no impeded gas exchange is expected. b) Rootability. The extremely deep soils with their relatively stable blocky structures and high porosity provide an environment suitable for unhampered root develop- ment and tuber expansion. c) Résistance to erosion. The area has a moderate to high resistance to erosion. The negative influence of high rainfall intensity and the undulating to rolling topography are partly offset by the favourable structure stability (low erodibility) of the surface soil. d) Ease of cultivation and scope for agricultural implements. Although the soils impose no serious limitations to manual land preparation and oxen ploughing, areas with a rolling topography are less suitable for tractor ploughing. Moreover, tractor ploughing generally leads to deter- ioration of the physical properties of the topsoil (compaction).
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5. Trial Design and Execution Plan, Kerugoya, Kirinyaga.
(Full details of the methodology for carrying out the trials are shown in Chapter IV of the main report.)
Selection of Crops: The proposed crop sequences in each of the three modules for the Kirinyaga Trial Site are:
Site 23.1 Kerugoya, RAINY SEASONS Kirinyaga 1st, Long, March 2nd, Short, Oct.
51 Standard Maize Hybrid 511 Katumani C.B. 52 Maize & Beans H.512 +GLP 2 Beans K.C.B.+GLP 2 Beans 53 Potat./Cabb.; Beans Anne t/Copenhagen GLP 2 Beans
The 1st sequence or module is continuous, pure maize, twice/year. The 2nd is intercropped maize and beans also twice/year. The 3rd is potatoes or cabbages in the 1st rains, and beans in the 2nd rains. In October 1986 when starting up the site, Annett potatoes were planted in this module.
Each module contains 2 experiments, namely Experiment 1 and Experiment 2. Experiment 1 is a 4N x 4P factorial, with 2 replications in each module. Experiment 2 is a 2NP x 2K x 2L x 2 FYM factorial, also with 2 replications in each module.
Each module thus consists of 64 plots, and the total for the 3 modules is 192 plots.
FYM will be applied only during the October rains, as the trial here started in October. Mineral fertilizers will be applied in both rains. Where maize and beans are intercropped, the fertilizer will be given to the maize. The intercropped beans will not receive any fertilizer directly at planting, but will "scavenge" from the maize, and from residual fertilizer left after the first season.
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