We need to aim for ecological intensification of agroecosystems, in order to cover an increasing global food demand while decreasing agricultural inputs such as fertilisers is required to maintain ecosystem services. Increasing the efficiency of nutrients to plants while decreasing nutrient inputs means that better exploration and exploitation of soil resources must be achieved in agroecosystems. This paper focusses on intercropping, which proved efficient to increase agroecosystem productivity, via better exploitation of soil resources. We studied the underlying processes of acquisition of soil phosphorus (P) by plants in cereal/legume agroecosystems, with a particular focus on rhizosphere processes. The working hypothesis is that the two intercropped species may access different P pools, the legume being responsible for greater changes in P availability in the rhizosphere, as a consequence of root-induced acidification resulting from nitrogen fixation. We sampled the rhizosphere of field-grown plants at two stages of growth of durum wheat and pea/faba bean along a gradient of soil P availability. Available P increased in the rhizosphere, especially for the legumes, and more so when intercropped. This was possibly due to the increased proportion of nitrogen fixation in the intercropped legumes, thereby resulting in inter-species facilitation for P acquisition.
