Journal Article
Water scarcity and nutrient availability for rice farming have become great matters of
concern in the contexts of climate change and land use change globally. Both interact and contribute
to crop productivity at the expense of nutrients and future water sustainability. The objective of
this study was to understand the on-farm potential response of soil organic carbon (SOC), total
nitrogen (TN), and total phosphorous (TP) to water management practices in rice farming within the
Kilombero Valley, Tanzania. Soil samples were collected from three villages in the study area at four
depths: 0–20, 20–30, 30–40, and 40–50 cm. Four water management regimes, namely: A = traditional
flooding (rainfed) without intensification of rice farming; B = traditional flooding (rainfed) involving
a system of rice intensification (SRI); C = alternative wetting and drying (AWD) involving SRI for
one cropping season; D = abandoned fields (fallow); and E = AWD involving SRI for two cropping
seasons, were investigated as regards their impact on SOC, TN, and TP. There were significant
(p < 0.05) effects of water management regimes on SOC, TN, and TP. AWD involving SRI for one
cropping season indicated a positive effect on SOC and TN across all depths as compared to other
practices. We conclude that water management practice that involves AWD with SRI for one cropping
season is a plausible approach to maintaining high SOC and TN, with the potential for increasing
crop production while minimizing water consumption