Improving crop productivity and water use efficiency in basin rice cultivation in Kenya through SRI

Abstract

Improving the yield of rice (Oryza sativa L) in existing irrigated areas rather than further expansion is more likely to be the main source of growth for the crop in Kenya, especially due to limited land and water resources. In order to achieve this, there is need to identify and adopt solutions that are environmentally more sustainable. That is, the production systems adopted should reduce water consumption and increase productivity. This study evaluated whether the System of Rice Intensification (SRI) could increase water use efficiency and crop productivity relative to the conventional production system of continuous flooding. The effects of SRI on total water input and the growth characteristics of three rice varieties were investigated in a split-plot factorial at the experimental farm of the Mwea Irrigation Scheme of Kenya during the August - December 2009 growing season on vertic clay soils. The production practices of SRI were found to be beneficial to rice growth. SRI gave higher average grain yield (14.85 t/ha) than the conventional production system (8.66 t/ha) at P=0.006, while the average yield across production systems was 15.89 t/ha, 11.26 t/ha and 8.10 t/ha for BW196, NERICA1 and Basmati370 varieties respectively, with P<0.001. There was a 24% saving in irrigation water by SRI, while crop productivity and water use efficiency increased by 71%, 90% respectively due to SRI. Overall, SRI production system gave better yield and productivity results than the conventional flooding system. This was probably as a result of better phenotypic expressions due to the innovative soil-water-crop management practices of SRI that change the environment where rice is grown.