Towards a diversified agriculture: Mixing cereals with legumes in Mediterranean farming systems

Introducing diversification in the intensive monocropping systems is an essential requirement to achieve a sustainable agriculture. Plant mixtures are a useful tool to bring about diversification and choosing the right components of those mixtures is key to succeed in this strategy. Legumes are a good component for plant mixtures, especially for their ability to enrich the fertility of the soil. They can be an ideal partner for cereals, both for their complementary ecological behavior and for adding highvalue vegetal protein to the final harvested product. In the frame of past FP6-GLIP and FP7-LEGATO projects we were involved in a series of cereal/legume intercropping experiments to study their effects reducing pests, diseases and weeds. Currently, in the frame of H2020-DIVERSify, among other activities, we are assessing yield benefits. We describe here experiments performed in Almodóvar del Río, Córdoba, started in season 2017-18. In one of them wheat was combined with faba bean and in the other one barley was combined with pea. In each of them, two cultivars of each crop were used in all possible combinations in a randomized block design with four replications. Proportion of crops in both cases was 50/50. Plot size was 1.2 x 10 m. Results from first year on the wheat/faba bean mixture pointed to an increase of up to 20% in faba bean yield, no effecting wheat yield. On the contrary, in the barley/pea mixture, the pea yield was reduced, while barley remains unaffected. This suggests that the proportion of pea should be increased in the mixture, what is being tested this second season. No reduction was observed on Septoria blotch on wheat, or on net blotch on barley. Trials are being repeated for a second season, paying attention also to weed, pest and disease suppression.