Exploring trade-off and synergy for improving irrigated rice-based farming systems in the Senegal River Valley

Rice is the staple food for millions of people in Senegal. However, only about 40% of total rice consumption is satisfied through domestic production. The Senegalese government aims to increase rice production in the Senegal River Valley (SRV) through promotion of double rice cropping and reduction of yield gap with improved management practices. The objectives of this study were to (1) describe the main drivers influencing irrigated rice-based farming systems, (2) characterize current farming systems functioning along with farmers? strategies, and (3) investigate trade-offs and synergies between production, economic, social, and environmental performance indicators of irrigated rice-based farming systems. Farming systems functioning and their main drivers were qualitatively analyzed through data collected through interviews in the Delta and the middle valley of the SRV. The FarmDESIGN model was used to quantitatively evaluate farm performance indicators. We considered rice production, farm profit, leisure time, and N balance as production, economic, social, and environmental performance indicators. Cropping systems differed between two locations and across farmers. Major crops were rice, tomato, and onion. Rice is grown in the wet and hot dry season, while two vegetables are grown in the cool dry season. Farms with large areas had more options and room for improvement than small farms. Double rice cropping was more common in the Delta than in the middle valley. Rice grown in the hot dry season produced higher yields and was perceived to have lower risks than rice grown in the wet season. As a result, farmers massively shift rice cultivation from the wet season to the hot dry season. Tomato and onion cultivation in the cool dry season was more profitable, more time-consuming and had larger N losses to the environment than rice cultivation. The major risk for vegetable cultivation was household self-sufficiency for rice, since rice and vegetable cropping calendars could overlap (end in the cool dry season and start in the hot dry season). Furthermore, lack of financial and technical support, high labor requirements, and lack of knowledge on vegetable cultivation are major constraints to their cultivation. Finally, crop diversification from rice cultivation was desired by most farmers, but smallholder farmers had limited room for their decision making due to institutional and financial service arrangements, and land size. Results from FarmDESIGN model indicate that farm profit can be increased with reduced household leisure time and increased N losses, and rice production could be increased by cultivating rice in the hot dry season in the fields currently dedicated to vegetables. The latter option can reduce farm profit and N losses, but increase household leisure time. In conclusion, there are substantial trade-off and synergy in irrigated rice-based farming systems in the SRV. The government policy for enhancing rice production through promotion of double rice cropping is not likely to be effective for farmers aiming for high profit. Technical, financial, and institutional supports to smallholder farmers are essential for developing both vegetable and rice sectors in the SRV.

Kazuki Saito, Pepijn A.J. van Oort, Diagne Mandiaye, Jeroen C.J. Groot Antoine G.L. Brosseau, 'Exploring trade-off and synergy for improving irrigated rice-based farming systems in the Senegal River Valley', Win more, lose less: Capturing synergies between SDGs through agricultural research, CGIAR, 2018