Comparison of Yields of Paddy Rice Under System of Rice Intensification in Mwea, Kenya

Abstract

Rice (Oryza sativa L.) is the world’s most important food crop and a major food grain for about half its population. It is also the greatest consumer of water among all crops and uses about 80% of the total irrigated freshwater resources in some countries. The conventional paddy system of rice production depends on a continuous supply of water for irrigation. With rapid population growth, and a change in eating habits due to urbanization, annual demand for rice continues to grow, and it presently exceeds the Kenya national annual production by about 200%. To meet the demand for rice with the limited water resources in a sustainable way, new innovative ways of rice crop production are needed. System of Rice Intensification (SRI) is an innovation that offers farmers an opportunity to reduce their water demand while increasing rice yield. Field experiments were conducted in 2010 and 2011 seasons at the Mwea Irrigation Agricultural Development (MIAD) centre located in the Mwea Irrigation Scheme (MIS), Kenya to compare yields of three rice varieties (Basmati 370, BW 196, and IR 2793-80-1) grown under SRI management with reduced water applications versus conventional practices of continuous flooding (CF). SRI gave the highest yields and water savings for all three rice varieties, on average increasing yield 1.7 t ha-1, 3.4 t ha-1 and 3.3 t ha-1 for the Basmati 370, BW 196, and IR 2793-80-1 varieties, respectively, while the water savings were 2,983 m3 ha-1 3,714 m3 ha-1 and 3,791 m3 ha-1. Similarly, water productivity for the three varieties averaged 140% higher under SRI management (1.2 kg m-3 vs. 0.5 kg m-3). These findings are consistent with similar evaluations in other countries.