Can sustainable agriculture really feed the world?

updated August 2010

Well, consider the definition of "sustainable."

Agriculture that is not sustainable will certainly not be able to feed future generations. Agriculture that is not sustainable will lead to the degradation of the soil and water resources that are required for crop production. Agriculture that is not sustainable will require ever-increasing inputs of fuel, fertilizer, and pesticides to give yields that do not keep pace with input levels.

We know where the question is coming from. There is a lot of disagreement over what practices are "sustainable" versus "not sustainable." Many practitioners and promoters of sustainable agriculture think of organic agriculture as a model of sustainability because it requires no use of synthetic pesticides or fertilizers. Nobel Prize winners including the late Dr. Norman Borlaug, leader of the "Green Revolution," have come out publicly against organic agriculture, claiming that if widely adopted it will lead to food shortages and environmental degradation. See: "High-yield Conservation Protects Biodiversity."

Part of the disagreement stems from differing ideas about the yield potential of organic and sustainable agriculture.  Organic agriculture has been presented by some of its critics as capable of only about 50% of the yield of conventional agriculture, at best. The critics then claim that modern, "conventional," high-input agriculture is more environmentally friendly than organic because fewer acres are needed to produce the needed yields, so more lands can remain wild.  Recent modeling of the climate impacts of high-input, high-yield agriculture by researchers at Stanford University supports that view.

Modeling rests on assumptions, however, and the assumption that organic or sustainable agriculture must yield less than high-input conventional agriculture is not necessarily true.  If done poorly it certainly will yield less, and some of the low yields for organic crops that have been reported in the past were due to poor agricultural practices.  Researchers and practitioners of sustainable agriculture have been steadily raising the bar on yields.  There is research that supports the viewpoint that organic agriculture, done well, can yield as much as "conventional" high-input agriculture.  Christos Vasiliokos of the University of California at Berkeley reviews the findings of some of this research from the 1990s in his article, “Can Organic Farming ‘Feed the World?” (PDF, 165 kb)

More recent modeling studies from the University of Michigan show equivalent yields from organic and conventional agriculture in developed countries, and much greater yields from organic methods in developing countries.

Long-term research (PDF, 4.17 Mb) into organic systems at the Rodale Institute has shown yields comparable to conventional agriculture, as well as potential to fix nitrogen without petroleum-intensive synthetic fertilizers and with fewer system losses of nutrients to the environment.

Long-term research begun in 1998 in Iowa has shown improving soil health over time in fields under organic management.  Over the 12 years of the study organic and conventional corn yields have been very close, with organic yielding higher in some years and lower in others. View more research reports from the Iowa studies here.

In any discussion about feeding the world, we need to have a word about biotechnology. Biotechnology in the form of genetic engineering of crops is often presented as part of the high-input, high-yield, conventional agriculture package that is necessary to feed the world.  Some proponents of this system have made statements that those opposing their views are "anti-science."  For example, “Listen to sound science on agricultural technology,” by C. S. Prakash and Martina Newell-McGloughlin.
There are many scientists and scientist groups that support sustainable agriculture and question the use of genetically engineered crops. The Union of Concerned Scientists promotes sustainable agriculture, questions the application of genetic engineering to food plants, and documents negative impacts of cropping systems that use genetically engineered crops.
Of course, discussions about feeding the world have to take into account issues of poverty. High-input, high-yield conventional agriculture (including genetically engineered crops) is frequently touted as the way to feed the hungry people of the world. This was the basis of the Green Revolution for which Dr. Norman Borlaug received a Nobel prize.  Hunger activists point out that many of the poorest, hungriest people have no land on which to grow crops and no money with which to buy food. Poor and hungry people who do have access to land cannot afford the seed, fertilizer, and pesticide inputs required to produce the Green Revolution crops. Reducing hunger, then, depends on reducing poverty; not necessarily on producing more quantities of food. For lots of background on this topic, see "Readings on Poverty, Hunger, and Economic Development."
Organizations such as the Food and Agriculture Organization (FAO) of the United Nations are looking to sustainable agriculture to help impoverished people feed themselves and earn money.

Dr. Jules Pretty of the Centre for Environment and Society, University of Essex, United Kingdom, prepared a report titled "Reducing Food Poverty with Sustainable Agriculture." This report, published in 2001, documents worldwide success in reducing poverty through sustainable agriculture projects that give local people the means to produce their own food.