Push-pull technology improves carbon stocks in rainfed smallholder agriculture in Western Kenya

Push-pull technology improves agricultural productivity. However, its long-term effect on biomass carbon and soil organic carbon (SOC) is not yet known. The aims of this study were: to assess the effect of push-pull technology on (1) biomass carbon and (2) SOC, considering climatic conditions and the length of time that push-pull had been practiced on a farm; and (3) to establish the relationship between biomass carbon and SOC on farms. Aboveground biomass carbon and SOC were measured on 36 farms in western Kenya, encompassing three contrasting sites (Bondo, Siaya and Vihiga) and six cropping systems (push-pull and five non-push-pull systems). Farms in western Kenya stock between 3.0 +/- 0.3 and 4.0 +/- 0.4 t C ha(-1) in crop biomass and between 24.4 +/- 2.1 and 37.0 +/- 2.6 t C ha(-1) in the soil for those practicing push-pull, and between 1.1 +/- 0.3 and 2.1 +/- 0.2 t C ha(-1) biomass carbon and between 19.2 +/- 2.1 and 31.1 +/- 1.7 t C ha(-1) soil carbon for those without push-pull. There was no correlation between biomass carbon and SOC. Adoption of push-pull offers opportunities to mitigate climate change through carbon sequestration in plants and soils in low-, medium- and high-rainfall environments in both long and short rain seasons.