Combining cash crops with companion species to deliver ecosystem services

The article reports on field trials of two intercropping systems: winter oilseed rape sown with companion species at the start of its cycle, and winter wheat under-sown in relay with legume cover crops. Both associations reduced weed biomass and ground cover compared to sole crops. In unfertilized rape trials, companion plants contributed an average of 10 kg N/ha in spring, while relay-intercropped legumes enhanced nitrogen uptake in the following wheat by over 50% compared to the control. Leguminous mixtures emerged as the most effective companions, allowing fertilizer reductions of 30–60 kg N/ha without yield penalties. Establishing a robust companion cover was identified as critical for success.