Project Final Report: Optimized Shrub System: Improving Cowpea Yields and Strengthening Smallholder Resilience
From the January 2024 Newsletter
West Africa suffers from recurring drought and degraded soils which limits productivity of cowpea, an important source of protein and income for rural households in the Sahel. This project pilot tested and adapted the Optimized Shrub System (OSS) to improve cowpea production in Senegal. OSS utilizes 2 indigenous shrubs (Guiera senegalensis and Piliostigma reticulatum) at densities of 1200-1500 shrubs/ha that includes annual incorporation of aboveground biomass – a system our research (34+ refereed journal articles) has shown dramatically increases crop yields (pearl millet and peanut), remediates degraded soils, and profoundly, shrubs can “bio-irrigate” adjacent crops – a powerful mechanism to combat in-season drought.
On-farm evaluation in collaboration with 30 farming households pilot testing a locally adapted, gender sensitive OSS in side-by-side comparison plots with the Traditional Management System (TMS - low shrub density and annual burning of coppiced biomass) showed that after three years, yields of millet increased by 54% with OSS over the TMS when managed by farmers.
Eight cowpea varieties that varied in duration and phenotypic properties were tested to identify superior lines for OSS. Five cowpea varieties in the same study had cowpea seeds analyzed for four nutrients which showed that OSS increased seed content of three of the four nutrients. Considering both productivity and nutritional value, the varieties Kelle and Yacine were the top performers and best adapted to be grown under OSS management.
The project also supported two master degree students, and project outputs have been and will continue to be shared through journal publications, OSS Field Days, website blogs, and the OSS SAWBO video as well as through the OSS-focused non-profit, Agro-Shrub Alliance.