November 2, 2011 | Deanna Krinn

Researchers at the Penn State College of Agricultural Sciences were recently awarded a $2.3 million grant by the U.S. Department of Agriculture to examine the effects of various “cover crop cocktails,” or cover crop mixtures, on organic agriculture production.

Jason Kaye, associate professor of soil biogeochemistry, said the study hopes to determine whether mixing multiple varieties of cover crops or planting a single species is better at amplifying ecosystem functions in a corn-soybean-wheat cash crop rotation that produces organic feed and forage.

“We will be planting cover crop mixtures that target nutrient supply, nutrient retention, weed suppression and management ease,” he said. “We’ll test the idea that diverse mixtures provide these functions better than cover crops in monoculture.”

Since organic farms do not use synthetic and chemical fertilizers and pesticides, they are dependent on sustainable methods of weed management and nutrient optimization. Cover crops work to suppress the weed population and can feed nutrients back into the soil, and the study will give Penn State researchers the ability to learn even more about the role of cover crops in organic food production.

“Most studies focus on one function, but we will measure simultaneous effects on nutrient supply, nutrient retention, weed suppression, insect pest regulation, soil quality, erosion control, yield and short-term profitability,” he said. “We think it is important for agricultural research to include a number of ecosystem functions because we expect tradeoffs among them. For example, treatments that maximize nutrient supply may not be optimal for weed suppression.”

The popularity of organic foods in the United States has grown in recent years, with more than two-thirds of consumers purchasing organic products at least occasionally, according to the USDA. But in spite of this growth in popularity, Kaye states the amount of research into cover cropping is lacking.

“To fill this gap, our long-term goal is to quantify and translate the benefits and trade-offs of using diverse cover crop mixtures in organic feed rotations,” he said. He goes on to state that using a range of plant species increases biodiversity and enhances produce output and is a large component of organic farming philosophy.

Penn State researchers will collaborate with a cover crop seed company, other farmers, and farmer networks at the university’s Russell E. Larson Agricultural Research Center at Rock Springs, PA. to increase the study’s potential impact on regional organic agriculture.

The Penn State research grant to examine the impact of various cover crops on organic food production is one of 23 that were awarded in 18 states by the USDA. The purpose of the grants is to support research and extension programs working to help organic producers and processors grow and market their products more effectively.

“As more and more farmers adopt organic agriculture practices, they need the best science available to operate profitable and successful organic farms,” said Kathleen Merrigan, deputy agriculture secretary, in announcing the grants.

SOURCE: http://live.psu.edu/story/56088