Intercropping Cereals with Legumes for Soil Fertility

This manual details the EcoStack project's research on intercropping cereals (winter wheat, spring barley, winter barley) with forage legumes (berseem clover, white clover, crimson clover, bur clover) across eight European countries from 2019 to 2022. It evaluates ecological and economic benefits, including enhanced soil fertility through nitrogen fixation (~50 kg/ha), improved erosion control, and increased natural enemy abundance. Key practices include sowing legumes at 13 kg/ha (5 kg/ha berseem or crimson clover, 3 kg/ha white clover), using small broadcasters or harrows for even distribution, and maintaining post-harvest legume covers of at least 2 t/ha for soil protection. Results show modest aphid suppression and yield stability, though low biomass under dry conditions limited gains. Challenges include higher seed costs, machinery adaptation for direct seeding into living mulch, and trade-offs when harvesting legumes for forage. The approach supports sustainable intensification, reducing fertilizer use and enhancing ecosystem resilience across diverse European agroecosystems.