Pesquisa sobre arroz: acesso aberto

Abstrato

20 Years of Water Management Research for Rice in the Sub-Saharan Africa

Surya Naryan Duku

Rice is one of the major staple foods in sub-Saharan Africa (SSA) and is mainly grown in three environments: rain fed upland and rain fed and irrigated lowlands. In all rice-growing environments, the yield gap (the difference between the potential yield in irrigated lowland or water-limited yield in rain fed lowland and upland and the actual yield obtained by farmers) is largely due to a wide range of constraints including water-related issues. This paper aims to review water management research for rice cultivation in SSA. Major water-related constraints to rice production include drought, flooding, iron toxicity, and soil salinity. A wide range of technologies has been tested by Africa Rice Centre and its partners for their potential to address some of the water-related challenges across SSA. In the irrigated lowlands, the system of rice intensification and alternate wetting and drying significantly reduced water use, while the pre-conditions to maintain grain yield and quality compared to continuous flooding were identified. Salinity problems caused by the standing water layer could be addressed by flushing and leaching. In the rain fed lowlands, water control structures, Sarah rice production system, and the Smart-Valleys approach for land and water development improved water availability and grain yield compared to traditional water management practices. In the rain fed uplands, supplemental irrigation, mulching, and conservation agriculture mitigated the effects of drought on rice yield.