Thirty years of agronomy research for development in irrigated rice-based cropping systems in the West African Sahel: Achievements and perspectives

Progress in research on site-specific nutrient management for smallholder farmers in sub-Saharan Africa

“…For example, without adequate land development (e.g. bunding and levelling) in both rainfed lowland and irrigated rice systems and proper weed management, nutrient management practices such as SSNM would not work effectively ( Becker and Johnson, 2001 , Haefele et al, 2000 , Ibrahim et al, 2021 ). Research is also needed to integrate and validate these different tools and approaches for more extensive evaluation in diverse and fully representative farming systems in SSA.…”

“…Average rice yields in SSA are 2 Mg ha −1 , which is less than half the global average, and the region relies on imports for more than half of its rice consumption. The low yield is mainly constrained by sub-optimum agronomic practices, including fertilizer management ( Ibrahim et al, 2021 , Saito et al, 2019 , Saito et al, 2021 ). We also included SSNM for maize and cassava in this paper, as they are also widely produced in SSA, and often grown by the same rice farmers.…”

Assessing genetic and agronomic gains in rice yield in sub-Saharan Africa: A meta-analysis

“…The distribution of studies (41 %, 34 %, and 25 % from irrigated lowland, rainfed lowland, and rainfed upland rice) across production systems is not entirely proportional to the distribution of estimated area under rice over these three systems (26 %, 38 %, 32 %) ( Diagne et al, 2013 ). This is partly because AfricaRice Sahel regional research stations in Senegal have had research focus on irrigated rice since 1976, and a lot of efforts has been made to develop improved agronomic practices and varieties ( Futakuchi et al, 2021 , Ibrahim et al, 2021 ). Furthermore, higher share of studies conducted in Côte d′Ivoire and Benin in this paper is also due to the fact of existence of AfricaRice research stations (for Benin, 2005–2017).…”

“…Meanwhile, Saito et al (2021) defined agronomic gain in yield as the difference in yield between improved agronomic practices such as alternate nutrient, water, and weed managements, and/or their combinations and the control, which can be typical farmers’ practices, recommended practices, or practices having no input (e.g., no applied fertilizer). Several review papers have summarized impact of improved agronomic practices on agronomic gain in yield in SSA ( Chivenge et al, 2021 , Chivenge et al, 2022 , Ibrahim et al, 2021 , Saito et al, 2021 ). For instance, integrated crop management practices for irrigated rice systems showed yield gain from 1.6 to 3.1 t/ha ( Saito et al, 2021 ), while improved nutrient management has resulted in agronomic gain in yield from 0.4 to 2.9 t/ha ( Ibrahim et al, 2021 ).…”

“…Several review papers have summarized impact of improved agronomic practices on agronomic gain in yield in SSA ( Chivenge et al, 2021 , Chivenge et al, 2022 , Ibrahim et al, 2021 , Saito et al, 2021 ). For instance, integrated crop management practices for irrigated rice systems showed yield gain from 1.6 to 3.1 t/ha ( Saito et al, 2021 ), while improved nutrient management has resulted in agronomic gain in yield from 0.4 to 2.9 t/ha ( Ibrahim et al, 2021 ). Site-specific nutrient management practices have been shown to increase yield gain on average by 0.5 t/ha ( Chivenge et al, 2021 ).…”