Improving rice yield, its stability, and nutrient use efficiency in sub-Saharan Africa using good agricultural practices

Increasing rice productivity is key to achieve rice self-sufficiency in sub-Saharan Africa (SSA) where current consumption surpasses local production, mainly due to low yield associated with sub-optimal management practices. Good agricultural practices (GAPs) – considered as an integrated practices including soil, water, weed, pest, and disease management are critical in increasing farmers’ yields. However, there is a lack of comprehensive assessment of on-farm yield variation with GAPs across production systems and agroecological zones (AEZs) at the continental level. The objectives of the study were to (i) quantify yield variation with GAPs in three production systems and (ii) identify major production factors causing yield variation. From 2013 – 2022, GAPs were tested on-farm in 987 fields across 34 sites in 20 SSA countries. Yield data from GAPs plots were compared with farmers’ yields obtained from an independent yield gap survey. Yield with GAPs varied significantly (p < 0.001) across production systems and AEZs. Mean yields were 5.1, 3.9, and 2.5 t ha –1 in irrigated lowland (IL), rainfed lowland (RL), and rainfed upland (RU), respectively. Yield gain with GAPs averaged 0.7, 1.1 and 0.8 t ha –1 in IL, RL and RU; and was smaller in sites having higher farmers’ yields. Overall, 78, 87 and 88 % of the GAPs plots in IL, RL and RU, respectively, had higher yields compared with farmers’ yields. GAPs significantly (p = 0.01) reduced yield variation across production systems by 25, 29 and 20 % in IL, RL and RU, respectively. N, P and K use efficiencies, defined as partial factor productivity (kg grain/kg nutrient applied), were significantly (p < 0.001) higher in IL (59, 153 and 151 kg grain/kg N, P and K, respectively), followed by RL (47, 123 and 129 kg grain/kg N, P and K) and lowest in RU (31, 81 and 80 kg grain/kg N, P and K), with positive correlations between yield and N, P and K use efficiencies. Across production systems and AEZs, bunding, levelling, basal N, P and K and total N rates were among the top ranked management practices influencing yield, where high yielding plots were associated with good levelling and bunding. There is substantial potential to further increase productivity by improving on-farm management practices—particularly to enhance nutrient use efficiency—to close rice yield gaps across diverse production systems in SSA. The study contributes to better understanding of the effect of GAPs on yield and yield variation, and production factors that influence yield variation at a large geographical area of SSA. • Good agricultural practices (GAPs) were tested on-farm in 34 sites across 20 sub-Saharan African countries. • Yields were 5, 4 and 3 t ha –1 in irrigated lowland, rainfed lowland and upland. • Yield gain with GAPs was smaller in sites having higher farmers’ yields. • GAPs reduced yield variation across production systems and agroecological zones.