Analysis of Farming Practices through Soil Moisture and Sowing Date Adjustment of Rainfed Rice Cultivation in Central Benin, West Africa

Abstract

Demands for rice is increasing in West Africa, however, average yields are low, especially in the rainfed systems where the majority of the rice is cultivated. To understand the causes of low yield and appropriate managements for farmers, we conducted farmers’ interviews and a yield survey regarding sowing dates in Central Benin during 2015–2016. The interview results showed that rice yields positively corresponded with the seasonal rainfall, however, large yield variations were seen between farmers. We found that low-yield farmers (LYF, < 2 t ha^-1) significantly reduced their rice areas in comparison to high-yield farmers (HYF, ≥ 2 t ha^-1), especially after a dry cropping season. LYFs sowed rice and other crops at a significantly later date than HYFs. The yield survey results showed that sowing rice 3–6 weeks earlier than the average sowing date significantly increased yields for both farmer groups, due to higher soil moistures and terminal drought escape. The low yield in the LYF field was explained by low soil moisture content, delayed heading, reduced number of spikelets (m^-2) and low filled grain percentage. Cultivating rice on fields with high soil moisture is a prerequisite for high and stable yields in the rainfed systems. However, as yields of around 2 t ha^-1 were achieved on the LYF field by early sowing, the optimization of sowing dates could be considered as an effective method for increasing production and rice areas in the rainfed systems.