by and for Stoney Acres Farm
Last week we looked at the raw research data which compared yields for grains in organic and conventional agriculture. Beyond the straight comparison, is an analysis that looks more seriously at the practices of organic and conventional agriculture and their impacts on food security. When we consider more complex agricultural systems and how grains are currently used (not necessarily to feed people), the productivity and stability of organic systems seems to be of even more importance.
Despite corn and soy’s dominance of our agricultural landscape we must also take into consideration other crops, such as those eaten by people rather than cows, (or used to make ethanol… which confuses this ‘feeding the world’ question a bit.) In 2002 the Los Angeles Times reported on a 21 year Swiss study between organic and conventional systems examining a broader selection of crops. The comprehensive study, published in Science magazine, not only compared yields but examined other claims by studying energy use, inputs, and pollution. Organic crop yields averaged about 20% less than conventionally farmed crops, although the differences covered a wide range. At the low end, were potatoes due to challenges such as blight and the Colorado Potato Beatle yields were 58% to 66% of those produced by conventional means. The production of wheat reached 90% of a conventional harvest. Overall, organic farming methods used 50% less energy, 97% less pesticide and as much as 51% less fertilizer than conventional methods. While yields may not be equal the inputs that provided for those yields were dramatically lower. This point broadens the picture, for it is not simply a question of just yield but the resources used to achieve those yields. Also, the sustainability of those yields was not in question. After two decades of cultivation, the soil in the study's test plots was still rich in nutrients, resistant to erosion and readily water absorbent.
Organics’ dedication to soil health was evident in an apple comparison at Washington State. The six-year study published in Nature April 2001, concluded that organic apple farming was not only better for the soil and the environment than its conventional counterpart but had similar yields, higher profits and greater energy efficiency.
In a review of the Rodale Institute Farming Systems Trial comparing soil fungi activity, crop yields, energy efficiency, costs, organic matter changes over time, nitrogen accumulation and nitrate leaching across organic and conventional agricultural systems, David Pimentel, a Cornell University professor of ecology and agriculture, concludes, "Organic farming offers real advantages for such crops as corn and soybeans." Organic farming produces the same yields of corn and soybeans as does conventional farming, but uses 30 percent less energy, less water and no pesticides, induce less erosion, maintain soil quality and conserve more biological resources than conventional farming does. Pimentel is the lead author of a study that is published in Bioscience (Vol. 55:7).The study compared a conventional farm that used recommended fertilizer and pesticide applications with an organic animal-based farm (where manure was applied) and an organic legume-based farm (that used a three-year rotation of hairy vetch/corn and rye/soybeans and wheat). The two organic systems received no chemical fertilizers or pesticides. The research compared "First and foremost, we found that corn and soybean yields were the same across the three systems," said Pimentel, who noted that although organic corn yields were about one-third lower during the first four years of the study, over time the organic systems produced higher yields, especially under drought conditions in which organic corn and soy yields averaged 22% higher than conventional. The reason was that wind and water erosion degraded the soil on the conventional farm while the soil on the organic farms steadily improved in organic matter, moisture, microbial activity and other soil quality indicators. The fact that organic agriculture systems also absorb and retain significant amounts of carbon in the soil has implications for global warming as soil carbon in the organic systems increased by 15 to 28 percent, the equivalent of taking about 3,500 pounds of carbon dioxide per hectare out of the air.
To conclusively answer the original question Professor Ivette Perfecto and colleagues, at the University of Michigan's school of Natural Resources and Environment, analyzed published studies on yields from organic farming. They looked at 293 different examples. "Model estimates indicate that organic methods could produce enough food on a global per capita basis to sustain the current human population, and potentially an even larger population, without increasing the agricultural land base," they wrote in their July 2007 report, published in the journal Renewable Agriculture and Food Systems. Yields aside, not all aspects of these systems can be easily quantified regardless of their importance. As stated by the lead author in the Swiss Study "Costs like soil erosion, or pollution of ground water or climate change, these costs are not covered when you run comparisons between organic and conventional products. Society is paying these costs.” In the end, as these costs mount, yield is only one essential factor of any honest agricultural analysis. As fossil fuels deplete, and global warming changes the agricultural landscape, environmental sustainability must be a primary consideration for agricultural policy throughout the world. Organic is not only capable of feeding the world, it may have to.