Analysis of climate data and the associated risks to maize production in semi-arid Eastern Kenya

Abstract

Climate change is one of the most important constraints to agricultural production and food insecurity in marginal areas that rely on rain-fed production systems. Climate data for two analogue locations in semi-arid eastern Kenya was analyzed using Instat Plus V3.4 statistical package with the aim of determining changes and variability in seasonal and annual rainfall and temperatures, percentages of seasons with adequate rainfall for maize production, probabilities of dry spells in October–December rainfall season, and accumulated rainfall and soil moisture content relations at different maize growth stages. Analysis gave declining trends in both seasonal and annual rainfall amounts at rates between 0.15 and 2.1 mm per annum and increase of 0.040C and 0.030C in mean maximum and minimum annual temperatures, respectively. This is indicative of changes in climate and hence the need for early exploration of necessary mitigation strategies by all stakeholders and policy makers. There were high chances (> 90% probability) of dry spells in October and high percentages of seasons having less than 250 mm rainfall compared to those with more than 450 mm. Rainfall was low and poorly distributed over the crop growing season and soil moisture remained low even during periods of high crop water demand signifying the high risk involved in maize production and the need for introduction and popularization of alternative crops as well as water conservation measures during months of high rainfall. It also calls for specification of specific crops to be grown in the two seasons with different rainfall expectations.