Organic does it better

The longest and most comprehensive study ever to compare organic and conventional farming shows organic does it better. Organic methods are more energy efficient, kinder to the environment, and nearly as productive as regular farms for some crops. The results were published in Science, one of the two most prestigious scientific journals in the world, and may have significant political, scientific, and economic implications.

The study was conducted in Switzerland at the Research Institute of Organic Agriculture over a 21-year period. It compared yields and ecological ramifications of growing potato, winter wheat, and grass/clover crops using four different farming techniques. One conventional method relied on synthetic pesticides and soluble nitrogen for fertilizer.

A second conventional model used an “integrated” approach that includes manure with conventional techniques. The organic plots used manure fertilizers, naturally derived pesticides, and mechanical weeding. One organic system is relatively uncommon. Called “biodynamic” farming, it uses treatments such as a variety of herbs added to compost manure.

Over two decades, the average crop yield was about 20 percent lower in both organic fields, a finding on par with other studies. The best-performing organic crop was winter wheat, which yielded about 90 percent of the conventional harvest. Potatoes did the worst, with about 38 percent lower yields, mostly because of blight and potassium deficiency. The yields, however, are impressive considering that the organic plants got less than half the nutrients given to conventional plots.

The researchers also found that because no synthetic fertilizer had to be produced or applied, organic farming methods are more energy efficient, using up to 56 percent less energy per unit yield. Nutrient “inputs” of synthetic fertilizers, such as nitrogen, phosphorus, and potassium in the organic systems were 34 to 51 percent lower. Pesticide use was 97 percent lower.

“To use that much less and still get 80 percent of the conventional yields is outstanding,” says John Reganold, a professor of soil science at Washington State University, Pullman. “This study gives credibility to organic systems. They are viable and do so much else so well.”

Organic systems rely in part on organic soil activity, fertility, and better soil structure to achieve considerable yields. The trial found that the soils in the organic plots were 10 to 60 percent more stable, implying they’re less prone to erosion. Compared to conventionally grown crops, the organic plants had 40 percent more roots colonized by fungi that help them absorb nutrients. Organic soils also contained as much as three times more earthworms, twice as many spiders, and more pest-eating beetles, arthropods, and microorganisms. When judging microbial activity, biodynamic soil ranked even higher than in the standard organic methods.

Greater soil-organism activity, plus the greater diversity of insects and arthropods in turn helps support more biodiversity higher in the food web among birds and larger animals. When subjected to intensive fertilizers and pesticides used by conventional methods, soil microorganisms become stressed and make heavier demands on resources for their own survival. The researchers say there’s a definite correlation between efficient energy “inputs” and efficient production in the soil.

Reganold says that despite the hit on yields overall, “organic does it better than conventional when you look at the criteria for sustainability.” The sustainable criteria cited include producing adequate food, conserving resources, protecting soil and water, economic profitability, and social responsibility (such as paying workers well). Reganold says it’s important to recognize that organic methods can be utilized on small, middle, and large sized farms, and remain economically profitable.

He also points out that studies closer to home on other crops show that organic farming can produce yields equivalent to conventional. Organic apple yields, for example, are the same as conventional yields, he says. Reganold is in charge of WSU’s new organic farming major.