1. Andrew Thuo Kariuki A56/77793/2012 Supervisors:
ASSESSMENT OF SOIL HEALTH USING NEMATODE ASSEMBLAGE AND SOIL CHARACTERISTICS IN ARENOSOLS, CAMBISOLS AND VERTISOLS IN KENYA
Andrew Thuo Kariuki
A56/77793/2012
Supervisors:
Prof. J.W. Kimenju
Dr. G. Karuku
Dr. G.M. Kariuki
Prof. H. Melakeberhan

2. Introduction
Diminishing Cropland Productivity is threatened by excessive, wanton cultivation and deforestation (Hill et al. 1995b).
Cropland accounts for 31% of Kenya’s total area, contributing to 20% of GDP and 65% of Exports. (Republic of Kenya 2010)
Soil should be perceived as a “Living Body” hence Soil health quality assessment requires a prompt and direct analyses technique (Torrion, 2002).
Soil micro-organisms depict life processes taking place in soil (Neher, 2001).
Soil Nematode Assemblages act as key bio-indicators of Soil life processes. (Neher,2001;Fiscus & Neher, 2002) .

3. Nematode Trophic Levels
Introduction (cont..)
Nematode Fauna Fluctuations indicate changes in soil ecosystem functions (Kimenju et al. 2009).
Past Soil health assessment via nematodes has focused “Primarily” on Plant Parasitic Nematodes (Urzelai et al., 2000).
A New and Robust approach to assess entire soil food web via use of :-
Bacteriovores
Fungivores
Herbivores
Predators
Omnivores
(Ferris et al.,2005; Wardle et al., 2005).
Nematode Trophic Levels

4. Justification
-Dwindling Cropland due to soil degradation in Kenya necessitate the Need to optimize on under-utilized available croplands in Kenya.
-Nematode Assemblages act as Viable, Rapid and Accurate Tool for Monitoring Soil Health in Kenya due to their:
Presence in all Soil Trophic Levels
Change Sensitive Reaction (chemical & physical)
Differentiation btw Natural & Structural changes
Economical and Accessible

5. Objectives General Objective: Specific Objectives:
To develop accurate and scalable soil health-based models that address soil degradation using Vertisols , Arenosols and Cambisols of Kenya.
Specific Objectives:
1. To determine effect of seasonal variation and land use practices on nematode assemblage of selected soil groups.
2. To determine how soil properties influence nematode assemblage in selected soil groups.
3. To determine how socio-economic & local customs influence land use practices in selected soil group regions.

6. Methodology Soil Sites Identification (FAO 1974)
Total of 192 Geo-Referenced Samples
2 Farms
(24)
2UD Zones
(8)
Vertisols
Cambisols
Arenosols
Soil Sites Identification
(FAO 1974)
Central Province Sites
(Makuyu)
Lower Eastern Province Sites
(Makueni)

7. Methodology…. Questionnaire Administered- Socio-Economic Survey
Seasonal Sampling Schedule
Dry Hot Season
(192)
Rainy Wet Season
Dry Cold Season 1 2 3 4 5 6 7 8 9 10
192
200cm3 Soil for nematode extraction
200cm3 Soil Sample for Soil Property Analyses
Contingency Soil Sample
Compilation of Soil Variables
Soil Information
Questionnaire Administered- Socio-Economic Survey

8. Description of Lab Data to Collect
Nematode Data
Microscopic Genus Level ID (×400)
Trophic Levels
Genus Richness
Abundance Ratio
Maturity Index
Structure Index
Soil Properties -Physical Properties (Temperature, Sand%, Silt%, Clay%)
-Chemical Properties (pH, Ca, Mg, K, Na, Total N, Available P, Cation Exchange Capacity C.E.C., Organic Matter Content).
Socio Economic Survey- Land Use and Socio-economic info

9. Data Analyses
Data will be subjected to Analysis of Variance (ANOVA) using SPSS, GenStat & SAS.
Differences among the Soil Groups and Regions will be tested using ANOVA for the comparison if the F-value is significant.

10. Expected Output
Effect of seasons, soil groups and land use practices on nematode assemblage  established
Effect of soil properties on nematode assemblage under different soil groups determined
Msc Thesis
Three scientific papers

11. Work Plan Activities Soil Identification and 1st Season Sampling
2012
2013
June
July
August
Sep
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Soil Identification and 1st Season Sampling
Second Season Sampling
Socio Economic survey
Nematode enumeration
Data compilation
Data Analyses and thesis Writing
Submission

12. Budget Activity Quantity Unit cost Ksh Total cost (Ksh)
Data collection expenses / Nematodes Count/Soil Property Analyses
300,000
Subsistence and Travel 8
2000
16,000
Printing Papers Thesis
2 reams
500
1,000
Printing Draft Proposal & Final Thesis
200 Pages 10
10,000
Photocopying
400 Pages 2
800
Binding
5 copies 50
250
GRAND TOTAL
328,050

13. Thank You