A new study from scientists at the University of California Berkeley sheds some light on the old debate about whether or not organic farming could feed the world with its finding that the difference in size between organic and conventional crops is smaller than previous studies have shown. Even better, the study concludes that when organic farmers use standard good practices that diversify what they grow, the yield gap shrinks even further, to just 8 or 9%.
The jury’s been out on the real difference between organic and conventional yields
Why is this exciting news? We already have a large body of scientific evidence that indicates that organic agriculture can perform better on measures like impacts on biodiversity, soil fertility, and water and energy usage. But critics of organic agriculture have raised doubts about the ability of organic farming to provide enough food for a growing population because of a long-standing perception that organic farms don’t yield as much as conventional ones.
The debate over whether organic agriculture can yield as much as conventional farming has gone on for a long time, and it is not as simple a comparison as you might expect. There are a lot of variables, like climate, weather, soil type, and farming practices that make it tough to compare the systems side by side. We have just a few high quality long term comparison trials that attempt to answer this question, like the Farming Systems Trial at the Rodale Institute in Pennsylvania or the Long Term Agroecological Research Experiment at Iowa State University. Both of these studies show how a well-managed organic system can be just as productive as conventional farming techniques while also being better for the environment. However, on the other hand, two larger studies, (meta-analyses which tried to look at all of the available studies comparing organic and conventional yields) concluded that organic yields were on average 25% lower than conventional. 
A new study shows organic is producing more than previously believed
A new study called “Diversification Practices Reduce Organic to Conventional Yield Gap,” is the largest analysis on this topic to date. Researchers looked at 115 studies, three times more than previous analyses comparing organic and conventional yields.
The results were impressive. The new analysis found that organic yields were 19% lower than conventional on average, 5% less than previous studies. The most interesting findings, though, aren’t just these average numbers, they’re two factors that show the gap could be much smaller – or even non-existent – in the near future.
Some organic practices may be more productive than others
The authors suggest that diversification techniques like planting more than one kind of crop and multi-year crop rotations reduce the yield gap to 8 – 9%. This means that the more organic farmers put these techniques into practice (which are already common on U.S. organic farms), the smaller the average yield gap will become over time.
The more research, the better the results
The study also found “evidence of bias “ in the literature indicating that studies were more likely to be published if the results indicated higher yields for conventional crops compared to organic. This led the authors to conclude that the 19% average yield gap they report is likely an overestimate.
In addition to that bias, investment in research on organic agriculture has historically been quite low compared to conventional systems. Increased investment in research on organic management practices could result in significant increases in organic yields. Further, most of the research that has created modern crop varieties has not been focused on developing crops that would do well in low-input systems like organic. Therefore, research to develop crop varieties that are more suited to organic practices could boost organic yields even further.
Still, producing more food isn’t all it takes to feed the world
Of course, as the study authors point out, it’s important to remember that “a focus solely on increased yields will not solve the problem of world hunger.” Farmers around the world already produce enough calories to meet the needs of the world’s population. Unfortunately, the challenges of poverty, access, and distribution mean that far too many people still struggle to access enough healthy food.
The findings of this study should be a wake-up call to policy makers, universities, and others who have a say in how our agricultural research dollars are spent. An investment in research on organic agriculture is an investment in a more sustainable future, one where we can grow enough food for everyone and create environmental benefits at the same time. Indeed, the authors of this study conclude by saying that the shift towards more environmentally beneficial farming systems like organic agriculture is an “increasingly urgent necessity” given the magnitude of the environmental problems we face today. It’s one more step in the direction of a more sustainable food system to benefit us all.
 Ponsio, Lauren C., Leithen K. M’Gonigle, Kevi C. Mace, Jenny Palomino, Perry de Valpine, and Claire Kremen. “Diversification Practices Reduce Organic To Conventional Yield Gap,” Proceedings of the Royal Society B 282:20141396. Http://dx.doi.org/10/1098/rspb.2014.1396
 Seufert, et al. “Comparing the yields of organic and conventional agriculture.” Nature 485 (2012).Verena Seufert, Navin Ramankutty, and Jonathan A. Foley.
 de Ponti T, Rijk B, van Ittersum M. 2012 The crop yield gap between organic and conventional agriculture. Agric. Syst. 108, 1–9. (doi:10.1016/j.agsy.2011.12.004)