Cover crops are suites of non-marketable plants grown to improve soil tilth and reduce erosion. Despite these agronomic benefits, the use of cover crops is often limited because they do not provide a direct source of revenue for producers. Integrating livestock to graze cover crops could provide both an expeditious method for cover crop termination and an alternative source of revenue. However, there has been little research on the agronomic impacts of grazing for cover crop termination, especially in horticultural market-gardens. We conducted a 3-year study comparing the effects of sheep grazing to terminate a four species cover crop (buckwheat, sweetclover, peas and beets) with those of mowing on soil quality indicators, cover crop termination efficacy, and subsequent cash-crop yields. In addition, we tested the nutritional quality of the cover crop as forage. Compared with mowing, sheep grazing did not affect soil chemistry, temperature or moisture. Our study demonstrates that sheep grazing removed more cover crop biomass than mowing at termination. The assessment of nutritional indices suggests that the four-species cover crop mixture could provide high-quality forage with a potential value of US$144.00–481.80 ha−1 of direct revenue as a grazing lease. Cash-crop yields did not differ between previously grazed and previously mowed plots in the subsequent growing season. We conclude that integrating sheep grazing into market vegetable garden operations could make cover crops more economically viable without having adverse effects on subsequent cash crops.

Integrated crop–livestock systems in the tropical region are diverse and not well characterized. To better understand the conditions and potential of these systems, we characterized the spatial and social arrangement of integrated systems within a landscape context. Integrated systems are defined by biomass and nutrient flows, linking crop, livestock and human components of agriculture. The landscape is defined within a spatial framework of these flows. To understand the diversity of integrated systems in the tropics, we characterized three case study areas: Southern Mali, Brazilian Cerrados and Amazon frontier. Methodology was based on historical and descriptive approaches of these cases, mobilizing interdisciplinary knowledge of a large research team. This provided a retrospective view to discuss four key points about the future of integrated systems in the tropics: (i) importance of landscape structure for conception and adaptation of the integrated systems; (ii) key role of local institutions in managing such integrated systems; (iii) trade-offs between external and internal resources; and (iv) role of nitrogen to improve system efficiency. This paper concludes with the relevance of social sciences in the further development of integrated systems.