International audienceThe forecasted 9.1 billion population in 2050 will require an increase in food production for an additional two billion people. There is thus an active debate on new farming practices that could produce more food in a sustainable way. Here, we list agroecological cropping practices in temperate areas. We classify practices according to efficiency, substitution, and redesign. We analyse their advantages and drawbacks with emphasis on diversification. We evaluate the potential use of the practices for future agriculture. Our major findings are: (1) we distinguish 15 categories of agroecological practices (7 practices involve increasing efficiency or substitution, and 8 practices need a redesign often based on diversification). (2) The following agroecological practices are so far poorly integrated in actual agriculture: biofertilisers; natural pesticides; crop choice and rotations; intercropping and relay intercropping; agroforestry with timber, fruit, or nut trees; allelopathic plants; direct seeding into living cover crops or mulch; and integration of semi-natural landscape elements at field and farm or their management at landscape scale. These agroecological practices have only a moderate potential to be broadly implemented in the next decade. (3) By contrast, the following practices are already well integrated: organic fertilisation, split fertilisation, reduced tillage, drip irrigation, biological pest control, and cultivar choice

Intercropping is a powerful way to promote a more diversified plant community in the field, thereby enabling complementary and facilitative relationships. In these systems, legumes are a key functional group, and are highly valued for the agroecological services they provide. This review identifies the different complementarity and facilitation processes in soils in intercropped legume/cereal systems and the key role of soil microorganisms in these processes. The intercropped legumes/cereal systems reduce inter-specific competition by enhancing complementarity/facilitation processes thereby improving the exploitation of resources, which is, in turn, reflected in the increase in plant production corresponding to greater efficiency of the agroecosystem as a whole. Plant production, including above-and belowground biomass, is positively correlated with microbial abundance and diversity. This microbial life is assumed to play a significant role in the availability and transfer of soil nutrients to plants as well as in plant health and soil fertility. Although we are currently unable to identify a reliable and exhaustive pattern of plant-microbe interactions, perhaps simply because no universal relationship exists between plants and microorganisms, reliable scenarios reveal strong trends and define the conditions required for successful intercropping systems and microbial interactions. Given our incomplete knowledge of facilitation processes and belowground interactions, intercropping systems must learn from and apply the experience gained in successful experiments. Intercropping dynamics play a critical role in explaining the establishment of facilitative root interactions and finally suggest perennial plant associations may be more effective than annual ones.