ADA, Ohio -- With only a small percentage of cover crops incorporated into field crop rotations in Ohio, farmers are missing out on a plethora of benefits legumes or grasses may afford.
Rafiq Islam, an Ohio State University Extension soil scientist, said that cover crops serve a multitude of purposes: They reduce soil erosion, reduce nutrient leaching, store carbon, improve soil structure, increase water infiltration, reduce compaction, suppress weeds, enhance wildlife, fix nitrogen and serve as a forage product.
"Cover crops have many uses and should be considered an integral part of any farming system," said Islam, who also holds an appointment with the Ohio Agricultural Research and Development Center. "However, every cover crop species has its own niche and attributes for agricultural production, and knowing which ones to use for a specific crop or purpose is where farmers can gain the most benefits."
Islam is among several OSU Extension specialists who will be presenting a series of cover crop sessions during the Ohio State University Extension Conservation Tillage and Technology Conference. The event will be held Feb. 26-27 at the McIntosh Center of Ohio Northern University in Ada.
Cover crop topics will be covered during a daylong session on Feb. 26 from 9:30 a.m. until 6:35 p.m., and a special pre-conference program on Feb. 25, called The Science of Cover Crop Benefits. The program will be held from 8 a.m. until 5 p.m. and is a separate cost from the Conservation Tillage and Technology Conference registration fee.
Cover crops generally fall into two categories: legumes, which are mainly grown to fix nitrogen, and grasses, which can be grown to help manage the soil. Legumes include cowpeas, Austrian winter peas, red clover, sweet clover, hairy vetch, soybeans, and alfalfa. Grasses include cereal rye, annual ryegrass, sorghum Sudan grass, oats, wheat, speltz, triticale, buckwheat and Teff.
"Legume cover crops are typically used to produce homegrown nitrogen and to recycle phosphorous. Grass cover crops are used to increase soil carbon and soil organic matter, recycle excess nitrogen in the soil, and reduce soil compaction. Brassica crops are grown to loosen the soil, recycle nitrogen, and suppress weeds. Some cover crops are grown to suppress insects, disease, weeds, or attract beneficial insects," said Jim Hoorman, an OSU Extension educator. "Cover crops offer many environmental benefits to producers that increase farm profitability."
Islam, Hoorman, and OSU Extension educator Alan Sundermeier have developed a fact sheet, "Cover Crop Rotations After Cash Grain Crop," that provides an in-depth look at what cover crops are best suited for a specific field crop, production practice or crop rotation.
The following are some examples:
• Following wheat, if a farmer wants to fix nitrogen, the best cover crops to plant are cowpeas, Austrian winter peas, red and sweet clover, hairy vetch or soybeans.
• After late soybeans and corn, cereal rye is a good choice because it can be planted after normal soybean and corn harvest time and will still get quickly established. Cereal rye is winter hardy, adds much organic matter, and helps control diseases and nematodes.
• After wheat harvest, oats, Teff and cereal rye can be grown as an emergency hay crop.
• Following corn silage, cover crop choices include cereal rye, annual ryegrass, oats, cowpeas, Austrian winter pea, oil seed radish and turnips.
• For farmers wanting to sequester carbon, sorghum Sudan grass, cereal rye, annual ryegrass, triticale, oats, wheat, speltz and barley are their best choices because they have a high carbon-to-nitrogen ratio.
• Cover crops that require no herbicide to kill include oats, cowpeas, oilseed radish and turnips.
• To start up or enhance no-till fields, plant oilseed radish, turnips or sorghum Sudan grass.
• Cover crops that tolerate heat and drought include cowpeas, hairy vetch, sweet clover, sorghum Sudan grass, buckwheat, barley and Teff.
• Cover crops that require little cost to establish include sorghum Sudan grass, oats, cereal rye, sweet clover, red clover, wheat, barley and oilseed radish.
The researchers have also outlined which cover crops work best for fixing nitrogen, absorbing phosphorus, reducing compaction, preventing soil erosion, attracting beneficial insects, and requiring either high or low maintenance. The best cover crops for eight crop rotation scenarios are also listed.
Certified Crop Advisor credits in soil and water, nutrient management and crop management will be offered during the Conservation Tillage and Technology Conference. For more information on the conference, log on to http://ctc.osu.edu. Registration before Feb. 15 is $40 per day or $60 for both days. After Feb. 15, the one-day price is $50, and to attend both days is $70. The Science of Cover Crops Benefit pre-conference program is $40.
Conference sponsors include Ohio State University Extension, the Ohio Agricultural Research and Development Center, Northwest Ohio Soil and Water Conservation Districts, USDA Natural Resources Conservation Service, USDA Farm Service Agency, and the Ohio No-Till Council.