The concept of using cover crops to control weeds and increase soil organic matter and fertility is nothing new, but practice on the farm lags far behind the existing research.

Two farmers who learned as they used cover crops, also called green manure, shared their perspectives with the Green Land Blue Waters Iowa-based group that is studying long-term changes in the agricultural landscape. The two farmers represent opposite ends of the agricultural spectrum, but have many qualities in common including the flexibility and eagerness to try new ideas.

Bryan Davis plows down rye before planting in the spring.
Roger Lansink’s children (then 8 and 3 years old) stand in oats that grew to a height of 8 inches before plow down.
	Lansink also experimented with oil radish as a cover crop.

"There's a definite benefit to cover crops, especially if they're managed properly," said Roger Lansink, who raises organic corn, soybeans, barley, oats, field peas, buckwheat, cattle, sheep and chickens on 850 acres near Odebolt. He began using cover crops about 10 years ago, when he first started to farm organically.

Lansink uses oats, buckwheat and rye as cover crops. More recently he planted two acres of oil radish, a member of the brassica family with a heavy tap root, to break up compaction in heavy bottom ground rather than resorting to chisel plowing.

"It seemed to work pretty well, and we let cattle graze off the top," he said. "It's very difficult to get information about cover crops, but I think we're on the verge of figuring out just what we can do with them. It's very exciting."

Bryan Davis said he was looking at the bottom line when he started using cover crops about five years ago after relying almost entirely on no-till. He raises mostly corn and soybeans on 900 acres near Grinnell, using oats and rye as cover crops in his biological farming method that includes the addition of trace minerals.

"Compaction was a real problem for us and our yields were dropping in both corn and soybeans," he said. "I was having more erosion in my no-till situations than when I tilled because the soil wasn't getting the water infiltration."

He fall seeds rye, or spring seeds oats, then incorporates with a soil finisher or sprays with Roundup™ when plants are four to 10 inches tall. One pass with a Phillips Rotary Harrow provides adequate soil to seed contact when seeding the cover crops.

"Cover crops brought life back into my soil," Davis said, "and they can act as a form of herbicide and insecticide."

Within five years, Davis said he's increased his soil organic matter by from 2 percent to 4.5 percent, reduced nitrogen and herbicide inputs and maintained high yields. Last year on one 120-acre field he averaged 184 bushels/acre yield for corn while maintaining a break-even cost of $1.28/bushel, u sing just 16 pounds of applied nitrogen .

Davis said peer pressure can be a problem, "but you can't let it bother you."

Lansink agreed, adding that cover crops allowed him to raise products organically and increase soil organic matter by a full percentage point in just four years.

Green Lands Blue Waters launches Iowa learning group

The use of cover crops was the first topic of a new Iowa stakeholder committee involved in the Green Lands Blue Waters IOWA effort (GLBW IOWA). This group is part of a long-term program whose mission is to support development of and transition to a new generation of agricultural systems in the Mississippi River Basin that integrates more perennial plants and other continuous living cover into the agricultural landscape.

Members of the committee have allotted a year to learn more about the kinds of practices and opportunities that exist for Iowa farmers to transition to the kinds of agricultural systems proposed in the Green Lands Blue Waters vision. The committee meets quarterly, visiting with farmers and researchers about practices, barriers and opportunities. Coordinator is environmental consultant Del Christensen.

Members of the learning committee include representatives from ISU, the Leopold Center, Practical Farmers of Iowa, Iowa Farm Bureau Federation, ISU Extension and Extension to Value Added Agriculture, the Women, Food and Agriculture Network, Iowa Environmental Council, Des Moines Water Works, Trees Forever, The Nature Conservancy, Iowa Natural Heritage Foundation, ISU Research Farms, Iowa Soybean Association, Prairie Rivers RC&D, USDA/NRCS, the Iowa Departments of Agriculture and Land Stewardship and Natural Resources, University of Northern Iowa, Water for Iowans and numerous individual farmers.

The Leopold Center Ecology Initiative supports GLBW IOWA efforts through federal funds received for this purpose. These funds also support a half-time coordinator for the regional consortium, an evaluator, and a number of research projects on topics such as double-cropping field peas, living mulch and winter grazing.