Description

A poster presented at the 2012 Global Pulse Researchers Meeting, Kigali, Rwanda- “Transforming Grain-Legume Systems to Enhance Nutrition and Livelihoods”. Abstract: Bean genotypes with long root hairs, shallow roots, and many basal and adventitious roots acquire more P from low P soils. Field studies in Mozambique were conducted to assess the potential impacts of P-efficient bean genotypes with greater P extraction on soil erosion, biological N fixation, and intercropping with maize. P-efficient lines with shallower basal roots had greater biomass and canopy cover in low P soil, which reduced soil runoff from water erosion by one third compared with related lines with steeper basal root growth angles. Studies with 15N showed that P-efficient lines had 2 to 3 fold greater biological N fixation than related lines with steeper basal root growth angles. Intercropped with maize, the shallow-rooted lines reduced maize yield more than steep-rooted lines under low P, but this effect would be more than offset by the greater economic value of the increased bean yield caused by shallow roots. We conclude that P-efficient bean lines will enhance the productivity and sustainability of low fertility ecosystems by increasing bean yields, increasing biological N fixation, decreasing soil and water loss from runoff erosion, and by enhancing the profitability of maize/bean intercrops