Cornell researchers will study the use of cover crops in organic farming and how different organic farming practices affect yields, both with new funding from the U.S. Department of Agriculture Organic Research and Extension Initiative (USDA-OREI).
"Organic agriculture research has taken a long time to be taken seriously in the scientific community, though there are a great number of interesting scientific questions well-suited for study, and now we are getting real money to do that research," said Thomas Bjorkman, associate professor of vegetable crop physiology, who is project director for an $894,000 four-year grant from the USDA-OREI to study how summer cover crops such as buckwheat, sorghum-sudangrass and mustard can improve the biological processes underlying organic agriculture and how to transfer such knowledge to farmers.
Cover crops not only provide soil cover but also can suppress weeds, improve the supply of air, water and nutrients in soil and limit soil erosion, all of which are major challenges facing organic farmers.
"We'd like to see cover cropping as something that organic farmers do as a matter of standard practice," said Bjorkman, who is collaborating with co-project directors John Masiunas at University of Illinois-Urbana and Dan Brainard at Michigan State University. "It's effective, economical and not too complicated."
The research will determine appropriate production procedure, seeding and planting dates, and expected benefits to farmers from cover cropping. The researchers also will work with farmers to find the easiest methods for integrating such crops into their production systems.
"We want people to have success from the get-go," said Bjorkman.
The researchers are also developing a training curriculum for extension advisers so they might provide the best possible support to growers, said Bjorkman. And, the project will seek to make organic cover crop seeds available at reasonable prices.
"We began the research component on university farms this spring and are starting to work with growers to incorporate summer cover crops in their systems," said Bjorkman.
Charles Mohler, a senior research associate in the Department of Crop and Soil Sciences, also received a four-year USDA-OREI grant for $1.4 million to continue two experiments, one for grains and the other for vegetables, that began in 2005 to compare various organic growing strategies.
"We are mimicking what four different farmers would do, for both experiments," to see which methods maximize net profits, effectively cycle nutrients and build healthy soil, said Mohler.
In the grain experiment, the four strategies include: high nutrient input with poultry manure compost; a very low-input "bare-bones" system; intensive weed management with extra cultivation and high tillage; and a reduced tillage system that saves energy costs and time. Grains planted in a three-year rotation include soybeans, spelt and corn, with legume green manures that supply nitrogen for all systems.
The vegetable experiment uses four-year rotations of winter squash ( delicata ), cabbage, lettuce and potatoes. The four growing strategies include: an intensive management system that uses high compost rates to produce six crops in four years; an intermediate intensity system with the basic rotation of one crop a year and legume cover crops; a low intensity system that has one vegetable crop every other year, with cover crops and a period of bare fallow to reduce the weed seed bank; and a reduced tillage system with cover crops and vegetables planted in the bases of soil ridges.
In both experiments the researchers track soil nutrients, nutrient cycling budgets, weed populations, indicators of soil quality and economics to better understand the ecology of organic agriculture.