Produire des légumineuses à graines au moyen de l’association avec une céréale : cas de la lentille et du lupin blanc d’hiver

Grain legumes provide numerous nutritional, agronomic and environmental benefits and are at the core of the sustainability challenges of agricultural systems. Yet, grain legumes are hardly cultivated in Europe, not least because of strong agronomic constraints that reduce their yields and increase yield instability. Two PhD theses were performed to 1) assess the potential of intercropping cereals (wheat, triticale) with grain legumes (lentil and winter white lupin) to reduce the impacts of agronomic constraints on legume production; 2) better understand the functioning of these intercrops to improve their agronomic and economic performances. Intercropping legumes with a low density of cereal increased total grain yield in almost all tested situations compared to sole crops. The better global performance of intercrops was mainly due to a higher acquisition of light and nitrogen resources resulting from complementarities between species within the intercrops. Moreover, the presence of the cereal reduced weed biomass and lentil lodging. Intercropping legumes with cereals is thus a suitable agricultural practice to foster grain legume production in Europe

Evaluation of the STICS crop model within the INTERCROP EU project to simulate pea-barley intercropping systems.

This work is devoted to the evaluation and utilization of the STICS intercrop/sole crop model taking into account the European environmental variability within an organic farming framework. The model ability to simulate intercropping systems was evaluated on the network of the INTERCROP EU project experiments. We first realized the difficulty to simulate relevant absolute production values in spite of a satisfactorily phase of parameterisation in conventional farming experiments. We attributed most of the discrepancies between simulations and measurements to the non accounting of biotic stresses. However, the relative values and in particular the Land Equivalent Ratios draw to the same results for simulation and observa-tion, i.e. the global advantage of intercropping compared to sole crops. Those conclusions caused us to think that the use of the model to test technical strategies was worthwhile. Among the different strategies we tested with the model, one showed that intercropping was very interesting in term of stability, and an other showed that the inter-row factor was a better driver factor for choosing density design than global density