We hear a lot about food production these days – how it is actually a source of greenhouse gas emissions, and pollution. At the same time, there are rising rates of people suffering from overnutrition – an estimated 2 billion people who suffer from things like diabetes and chronic health disease from diets high in unhealthy food high in fat, salt and sugar. Yet there are also over 800 million people who are undernourished - they don’t get enough of and diverse food types. Paradoxically, many of those who experience hunger are themselves food producers. Finally, there are a lot of concerns about very large multinational companies who both sell the inputs to grow food (like fertilizer and seeds) and who sell the food products in large retail outlets.
Agroecology is an approach to growing food, which aims to address all of these problems within the food system. A holistic method, agroecology uses ecological principles to produce food, such as improving soil health, increasing biodiversity and building synergies between different parts of the food system. As an approach which arose in part from social movements concerned about rising inequity in food systems, agroecology also focuses on the social, economic and political aspects of the food system. Agroecological principles also include co-creating agricultural knowledge with food producers, reconnecting producers and consumers, ensuring that food systems are culturally appropriate, and fair. There are many different agroecological practices, some of which come from Indigenous food systems and others which have been developed through scientific experimentation. Agroforestry, for example, is the practice of growing trees with crops and sometimes animals, and has been used in traditional farming systems in many parts of the world. Cover crops, grown to reduce soil erosion and to improve soil fertility, is another agroecological practice. Having intercropped fields and mixed farming systems by increasing the number of crops and animals in a farm system are other examples of agroecological practices.
There have been many scientific reviews underlining the environmental benefits from such an agroecological approach, showing how it supports the core building blocks of our food system – soil, water, air, pollinators, and ensures long-term resilience of the food system. But some experts question whether such an approach can improve food security and nutrition, particularly for low and middle-income countries.
Our systematic review: Agroecology, food security and nutrition
We carried out a review to investigate the evidence that agroecology improves food security and nutrition. This review, which we began in 2018 as part of a United Nations Committee for World Food Security report on agroecology, was a ‘rapid review’ because we were not able to follow all of the steps of a systematic review. We carried out a search in several large databases of scientific articles, using key search terms for food security, nutrition and agroecology. This initial search yielded over 11,000 articles. We then screened the abstracts and titles to identify articles that were empirical studies of agroecological practices (either observational or intervention studies) which measured food security and/or nutritional outcomes. We identified 275 papers for a full text assessment, and in the end found 56 papers that met our criteria.
In our review of these 56 papers, we found that the majority (78%) found positive relationships between agroecological practices and food security and nutritional outcomes. There was only one study that found negative relationships, and some found both positive and negative outcomes. The food security and nutrition outcomes reported included dietary diversity, food security measures, and a few measured micronutrient intake for women or children, or child growth outcomes. Agroecological practices included increasing farm diversity (crop and/or livestock), integrating crop and livestock systems, improving soil health with additions of organic material, and some social aspects of agroecology such as increasing local market opportunities, supporting farmer-to-farmer training networks and addressing gender inequities within households.
Many of the studies (70%) only measured one or two agroecological practices, the most common ones being an increase in farm diversity and soil management. Those that had 3 or 4 agroecological practices were more likely to have positive impacts on food security and nutrition. More complex agroecological interventions often combined farm diversification with soil management, mixed crop-livestock systems or agroforestry, and some included social aspects of agroecology. Those studies that had more complex agroecological interventions also had more robust study design and analysis, such as longitudinal interventions. Notably, studies that had more robust evidence of impact also used participatory approaches to design interventions and address gender inequality.
There were multiple pathways that such improvement occurred – it may be that diets were improved directly through consumption of a more diverse range of crops and animals. It could also be that people sold a greater range of their farm products and used the money for household consumption. Improving soil health or integrating trees into the farm landscape can increase farm output and might also ensure greater yield stability and livestock health during times of drought or other extreme events. In addition, farmers might reduce the total amount of money spent on purchased inputs such as fertilizer. Finally, the social components of agroecology, such as addressing gender inequalities or connecting farmer networks, can help address other underlying drivers of food security and nutrition.
Overall, our review supported the hypothesis that more comprehensive uptake of agroecological practices will increase the chances of improving food security and nutrition outcomes. While we identified research gaps, particularly with more complex agroecological systems, and with more rigorous longitudinal research designs, this is the first comprehensive review of agroecology’s impact on food security and nutrition, and points to it as an important approach as the world grapples with ways to transform the food system.
Read the full paper in Global Food Security: Can agroecology improve food security and nutrition? A review