Crop-livestock integrated systems for more sustainable agricultural production: a review.

Integrated crop-livestock systems have been proposed as a method to sustainably intensify agricultural systems. However, it is important to understand what is known about these systems and where potential gaps are in our current knowledge. I reviewed over 116 different research and review articles focused on integrated crop-livestock systems and based on their focus, divided them into one of the three different aspects of sustainability: environmental, economic, or social. Most of the 116 articles focused on environmental (77) or economic (72) aspects of integrated crop-livestock systems, with 42 articles having both environmental and economic aspects. Of the 32 articles focused on social issues, there were 17 articles that included both environmental and social aspects and 13 articles that evaluated both economic and social aspects of integrated crop-livestock systems. Only nine articles evaluated all three aspects of sustainability in crop-livestock systems. Most social articles focused on potential adoption strategies, but there was little information about the impact that integrated crop-livestock systems have on the social fabric of communities. Other areas of limited research included how the spatial arrangement of different components of integrated crop-livestock systems may affect system synergies and the inclusion of multiple livestock species, including monogastrics, into these systems.