Improving Water Storage in Soils to Enhance Nutrient use Efficiency and Crop Yields for Enhanced Livelihoods of Small Scale Farmers in Semi-arid eastern Kenya

The current food situation in Kenya is alarming so that food is extremely expensive for the larger Kenyan population. This is largely due to the frequent droughts in the country and especially because more than 80% of the land is arid to semi-arid. There is therefore urgent need to put into practice existing technologies to spur food production in the semi-arid fragile ecosystems. This study is investigating the effect of trapezoidal bund technology and use of manure on soil moisture storage and retention, impact of soil moisture on nutrient availability and nutrient use efficiency by crops, nutrient dynamic changes in soil and effect on crop yields and long-term soil fertility maintenance. The study also aims to quantify microbial biomass and nitrogen mineralisation potentials in soils. The project is in progress at Katumani, Dryland Research Station in Machakos. Trapezoidal bunds for run-off water collection and storage have been constructed according to the recommended pattern. Plots measuring 4.5 m× 4.5 m will be used for the treatments where maize (var.SC Duma 43) and common beans are the test crops, and manure and NP fertilisers as source of plant nutrients. Three levels of both manure and NP fertilisers 0, 5 and10 tons/ha manure and 0,50 and 75 kg/ha of each N ad P fertilisers) will be used. Treatments will be factorial and randomised in a complete block. Soil moisture content will be measured by a gravimetric method. Simulation models for nutrient dynamics and crop performance will be done using CMKEN and NCSOIL models. Data will be subjected to analysis of variance and regression. Nutrient use efficiency and gross returns will be calculated.