Impact of Weather Analysis on Agricultural Production and Planning Decisions for the Semiarid Areas of Kenya

Abstract

Requirements for effective rainfall analysis and crop yield estimation are outlined. A case study is presented in which effective rainfall for maize at Katumani, Machakos District, was evaluated for each of the 48 wet seasons in a 24-yr period. The analysis takes into account rainfall, evaporation, soil depth and water holding capacity and growth characteristics of the crop influencing water uptake and yield. Dates of onset of rains were sortable into early (high-medium water adequacy for maize production), late (medium-low expectation) and too late for sowing. These expectations determined recommendations for sowing and fertilizer rates. Although unpredictable earlier, the rainfall pattern after onset fell into categories of high, medium or low adequacy for maize. Recommendations for final plant densities and N side dressing rates were based on these categories. Total season effective rainfall could be estimated 2 months before harvest, allowing final yield predictions.