Contributions of lateral flow and groundwater to the spatio-temporal variation of irrigated rice yields and water productivity in a West-African inland valley

Water management techniques to elevate rice yields and productive use of water resources in Africa, frequently lack a substantial spatial assessment as they are often based on plot level measurements without taking into account toposequential effects present in the landscape. These effects have been shown to significantly affect spatio-temporal variations in water availability and rice productivity in Asia. Therefore, this study addresses the spatio-temporal variations of the various water components within irrigated toposequences in an African inland valley and assesses its effect on water productivity and respective rice yields for two irrigation practices: (i) continuous flooding (CF), a well-known water management practice in rice cultivation used worldwide and (ii) a reduced irrigation scheme (RI) where irrigation is applied every 5 days resulting in a 1–2cm water layer after irrigation.