Assessing adoption and water productivity of the system of rice-intensification under farmer-led irrigation system in northern Tanzania

Abstract

This study was conducted to evaluate farmers‟ appropriation of the system of rice intensification (SRI) in an informal irrigation scheme in northern Tanzania. Understanding the integration and performance of SRI in the local rice farming will assist in short and long-term planning and allocation of available resources. First, a survey was conducted to explore farmers‟ adjustments of SRI principles. Second, yield and water productivity of the integrated system was assessed by setting up experimental plots in the farmers‟ fields. Four treatments representing farmers‟ adaptations of SRI practices were assessed. One treatment (F1) was continuous flooding while the other three treatments (F2, F3 and F4) were under intermittent irrigation. The yield of 4.8, 8.5, 8.2 and 9.2 tons/ha, and water productivity of 0.15, 0.39, 0.35 and 0.51 Kg/m 3 were obtained for F1, F2, F3 and F4, respectively. Water-saving under SRI was 34.3%, 28.9%, and 45.1% for F2, F3 and F4, respectively. The figures are comparable to those reported under full SRI, which is in the range 20% to 60%. The highest yield (9.2 tons/ha), water productivity (0.51 Kg/m 3 ) and water-saving (45.1%) was obtained in F4 involving one seedling 15 days old transplanted at 25 x 25 cm. However, this method is not preferred by many farmers due to lack of supporting infrastructure. Hence, F2 involving two seedlings 21 days old planted at 20 x 20 cm with intermittent irrigation is recommended for this area as it ensures a sufficient number of plants, relatively higher yields and a reduced considerable amount of irrigation water.