SummaryIntercropping is a farming practice involving two or more crop species, or genotypes, growing together and coexisting for a time. On the fringes of modern intensive agriculture, intercropping is important in many subsistence or low-input/resource-limited agricultural systems. By allowing genuine yield gains without increased inputs, or greater stability of yield with decreased inputs, intercropping could be one route to delivering 'sustainable intensification'. We discuss how recent knowledge from agronomy, plant physiology and ecology can be combined with the aim of improving intercropping systems. Recent advances in agronomy and plant physiology include better understanding of the mechanisms of interactions between crop genotypes and speciesfor example, enhanced resource availability through niche complementarity. Ecological advances include better understanding of the context-dependency of interactions, the mechanisms behind disease and pest avoidance, the links between above-and below-ground systems, and the role of microtopographic variation in coexistence. This improved understanding can guide approaches for improving intercropping systems, including breeding crops for intercropping. Although such advances can help to improve intercropping systems, we suggest that other topics also need addressing. These include better assessment of the wider benefits of intercropping in terms of multiple ecosystem services, collaboration with agricultural engineering, and more effective interdisciplinary research.

There is a great demand for high-protein materials for livestock feed in Europe and European agriculture has a deficit of about 70% high protein materials of which 87% is met by imported soybean and soy meal. This reflects the fact that grain legumes are currently under represented in European agriculture and produced on only 1.5 % of the arable land in Europe compared with 14.5% on a worldwide basis. Several grain legumes have the potential to replace at least some of the soya currently used in the diets of monogastric animals, ruminants and fish. There are also opportunities for greater use of legumes in new foods. Here we review the contribution of ecosystem services by grain legumes in European agriculture starting with provisioning services in terms of food and feed and moving on to the contribution they make to both regulating and supporting services which are in part due to the diversity which these crops bring to cropping systems. We explore the need to understand grain legume production on the time scale of a rotation rather than a cropping season in order to value and manage the agronomic challenges of weed, pests and diseases alongside the maintenance or improvement of soil structure, soil organic matter and nutrient cycling. A review of policy interventions to support grain legumes reveals that until very recently these have failed to make a difference in Europe. We contrast the European picture with the interventions that have allowed the development of grain legume production in both Canada and Australia. Whether farmers choose to grow more legumes will depend on market opportunities, the development of supply chains and policy support as well as technical improvements of grain legume production such as breeding of new varieties and management development to improve yield stability. However, to really increase the production of grain legumes in Europe the issues are far more wide reaching than agronomy or subsidy and require a fundamental rethinking of value chains to move grain legumes from being niche products to mainstream commodities.

Abstract. 12Complex relationships exist between different components of the organic farm and 13 the quantity and quality of the end products depend on the functioning of the whole 14 system. As such, it is very difficult to isolate soil fertility from production and complex interactions between different system components, fertility management in 1 organic farming relies on a long-term integrated approach rather than the more short-2 term very targeted solutions common in conventional agriculture.

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