Water Use Efficiency and Soil Nutrient and Physical Property Dynamics Under the System of Rice Intensification in Tanzania.

Rice plays a vital role in the Tanzanian economy and smallholder food security. However, increasing competing water demands as well as negative precipitation forecasts due to climate change threaten sustainable production of this staple food. The objective of this study was to evaluate the System of Rice Intensification (SRI) within the context of Tanzanian smallholder farmers. In particular, SRI was assessed with improved nutrient management practices on system water-use efficiency, yield, and soil properties and compared to conventional and regionally recommended practices. A field experiment was carried out over three seasons in Northern Tanzania. Treatments included conventionally managed flood irrigation and SRI consisting of planting younger seedlings, decreasing plant density, and applying half the amount of irrigation as the flooded treatment. Within each of the management regimes, there were two fertilizer management treatments of urea only (farmer practice) and application of NPK fertilizer. Both systems had similar yields, however, SRI achieved this with half the amount of irrigation. Additionally, nutrient balances and changes in key soil physical properties will be presented and discussed.