Friday, March 23rd, 2007
Cover crops could greatly decrease nutrients
Winter crops also could increase corn yields, extension educator says
By Nancy Allen
Recent studies on winter cover crops have shown great promise in tying up phosphorous and nitrogen, two nutrients abundant in the Grand Lake and Wabash River watersheds.
Jim Hoorman, of the Ohio State University Extension, spoke to a crowd of about 40 people Thursday at a Grand Lake/Wabash Watershed Alliance advisory board meeting. He is helping conduct studies on annual rye grass and cereal rye grass, two types of winter cover crops.
Watershed officials are promoting winter cover crops as a way to lessen soil erosion and keep excess nutrients out of the watershed. One of watershed coordinator Theresa May's objectives in the watershed action plan she is writing for the watersheds is to establish 2,000 acres of winter cover crops in the watersheds in three years.
"If we have a living, growing crop out there the whole time, then we can recycle nitrogen and phosphorous back to the next crop," Hoorman said. "If you're looking to tie up phosphorous and nitrogen, cover crops can do this."
Recent Ohio EPA water quality testing and flow studies indicate that most of the excess nutrients that enter the watersheds each year come in the fall and winter months, after crops have been harvested and manure is spread. Winter cover crops would help take up the nutrients from manure and lessen soil erosion, resulting in improved water quality.
Hoorman said studies have shown that cover crops are great at taking up nutrients and their extensive root systems help loosen compacted soil and improve yields of row crops planted in the same fields in the spring.
Winter cover crops also can be harvested, bailed and fed to livestock, he said. Annual rye and cereal rye typically grow best when planted in early September. It can then be killed off in early April with herbicide and then row crops such as corn and soybeans can be planted in the same field in the spring.
Hoorman talked of one farmer who greatly improved his corn yields by planting annual rye grass.
"He doubled his corn bushels over a four- to five-year period by planting annual rye," Hoorman said. "The corn was following the roots from the annual rye down to the water source."
Cover crops can help "break up hardpan soil with its extensive roots" and help improve and heal soil by decreasing unwanted bacteria levels and promoting the growth of beneficial fungus, Hoorman said.
"We have too much bacteria in the soil. We need more fungus to get better soil for growing crops," he said.
Planting cover crops also would help farmers comply with a USDA practice standard for spreading manure on frozen and/or snow-covered ground. Manure application on frozen and/or snow-covered ground is not recommended. However, if application is necessary, one of the criteria the practice standard says a field must have 90 percent residue cover such as hay or pasture. Cover crops would meet this criteria.
Hoorman told a story of a farmer who was able to get into a field planted in rye grass to spread manure in his wet field, when other farmers could not.
"It has such a dense, fibrous system a guy was able to spread his manure on it," Hoorman said, noting how it greened up and grew several inches in a few days.
Hoorman said winter cover crops would work best for livestock producers, especially dairy and hog farmers, who have manure to spread. He cautioned producers thinking about planting cover crops to start out slow by putting out a few acres at a time, preferably on fields they intend to spread manure on after harvest.
Following Thursday's meeting, Hoorman said the Wabash and Grand Lake watersheds would be a prime area in which to do cover crop studies. He said he would speak with May about going after grants to get a study funded.
During Thursday's meeting, May went over a list of 16 main objectives she has included in the watershed action plan and took written suggestions/comments from the crowd via index cards.
Information contained in the action plan will be vital for the plan getting state endorsement and to get grants that would help pay for conservation practices - outlined as objectives - that improve water quality. May hopes to have the plan completed in two months and submit it to the state for review.
Ohio EPA water quality testing has shown that the main contributor of pollution in the watersheds, in the form of sediment and attached nutrients, comes from farmland, which makes up 90 percent of the acreage in both watersheds.