The principal objections to the proposition that organic agriculture can contribute significantly to the global food supply are low yields and insufficient quantities of organically acceptable fertilizers. We evaluated the universality of both claims. For the first claim, we compared yields of organic versus conventional or low-intensive food production for a global dataset of 293 examples and estimated the average yield ratio (organic:non-organic) of different food categories for the developed and the developing world. For most food categories, the average yield ratio was slightly 1.0 for studies in the developing world. With the average yield ratios, we modeled the global food supply that could be grown organically on the current agricultural land base. Model estimates indicate that organic methods could produce enough food on a globalper capitabasis to sustain the current human population, and potentially an even larger population, without increasing the agricultural land base. We also evaluated the amount of nitrogen potentially available from fixation by leguminous cover crops used as fertilizer. Data from temperate and tropical agroecosystems suggest that leguminous cover crops could fix enough nitrogen to replace the amount of synthetic fertilizer currently in use. These results indicate that organic agriculture has the potential to contribute quite substantially to the global food supply, while reducing the detrimental environmental impacts of conventional agriculture. Evaluation and review of this paper have raised important issues about crop rotations under organic versus conventional agriculture and the reliability of grey-literature sources. An ongoing dialogue on these subjects can be found in the Forum editorial of this issue.

To address the challenges of biodiversity conservation and commodity production, a framework has been proposed that distinguishes between the integration (“land sharing”) and separation (“land sparing”) of conservation and production. Controversy has arisen around this framework partly because many scholars have focused specifically on food production rather than more encompassing notions such as land scarcity or food security. Controversy further surrounds the practical value of partial trade‐off analyses, the ways in which biodiversity should be quantified, and a series of scale effects that are not readily accounted for. We see key priorities for the future in (1) addressing these issues when using the existing framework, and (2) developing alternative, holistic ways to conceptualise challenges related to food, biodiversity, and land scarcity.

Summary2014 was the United Nations’ International Year of Family Farming, yet the importance of family farming for global food security is still surprisingly poorly documented. In a review of agricultural census data, we find that globally family farms constitute over 98% of all farms, and work on 53% of agricultural land. Across distinct contexts, family farming plays a critical role for global food production. We present two examples of policy approaches toward family farmers—Brazil and Malawi—to provide insight into some of the complexities and challenges behind the global numbers

The acceleration of ecological crises has driven a growing body of thinking on sustainability transitions. Agroecology is being promoted as an approach that can address multiple crises in the food system while addressing climate change and contributing to the Sustainable Development Goals. Beyond the more technical definition as, “the ecology of food systems”, agroecology has a fundamentally political dimension. It is based on an aspiration towards autonomy or the agency of networks of producers and citizens to self-organize for sustainability and social justice. In this article, we use the multi-level perspective (MLP) to examine agroecology transformations. Although the MLP has been helpful in conceptualizing historic transitions, there is a need to better understand: (a) the role of and potential to self-organize in the context of power in the dominant regime, and (b) how to shift to bottom-up forms of governance—a weak point in the literature. Our review analyzes the enabling and disabling conditions that shape agroecology transformations and the ability of communities to self-organize. We develop the notion of ‘domains of transformation’ as overlapping and interconnected interfaces between agroecology and the incumbent dominant regime. We present six critical domains that are important in agroecological transformations: access to natural ecosystems; knowledge and culture; systems of exchange; networks; discourse; and gender and equity. The article focuses on the dynamics of power and governance, arguing that a shift from top down technocratic approaches to bottom up forms of governance based on community-self organization across these domains has the most potential for enabling transformation for sustainability and social justice.