Current high input agricultural systems now rely on intensive production based on high fossil energy consumption and large-scale use of plant protection products and fertilisers. However, on the same time there is a growing consumer demand for healthy food, as well as increasing awareness of the need to preserve endangered environments and biodiversity and to limit greenhouse gas emissions and resource use. So, to increase the sustainability of production systems and preserve ecosystems, alternative and more sustainable methods of production need to be encouraged.
Transfer of knowledge and experience is the key for success when designing and introducing novel cropping system to increase agrobiodiversity in time and space, through e.g. cereal-legume intercropping. Farmers have to change a lot of old habits and form new ones in an ongoing process that begins with exposure to, and assimilation of relevant information.
Nitrogen is the most limiting nutrient in many agricultural plant production systems and the key challenge is to match the rate and timing of N supply to crop demand for N. Legume rotations and organic sources of nitrogen (N) fertility have progressively been replaced with synthetic N fertilizers over the past 3-4 decades. Future cropping systems will be more dependent on atmospheric N inputs through N2-fixation and recycling of N-rich residues to maintain soil fertility. Increasing emphasis on environmentally sustainable development with the use of renewable resources is expected to increase interest in the capacity of legumes to supply N to cropping systems of the future. On the same time, expected increasing and more unpredictable seasonal precipitation patterns together with the turnover of easily decomposable leguminous crop residues may results in N losses to air (N20), ground and surface waters (NO3-).
It is expected that inclusion of legumes in arable and vegetable cropping systems would increase diversity-driven agroecological services, namely crop yield, yield stability, weed suppression and soil fertility in all environments.