If you aren't offering your growers cover crop tips and inputs, you and they may be missing out. Fast growing companies are springing up to fill the gap, and cover crop acres are growing fast. This year's drought is feeding the frenzy and creating even greater need for “between crop” crops. Shortages of popular cover crops are reported and expected to get worse and for good reason.
"There are a couple of issues this fall that have raised interest in cover crops," said Hans Kok, coordinator, Indiana Conservation Cropping Systems Initiative. "The enormous shortage of forage and hay, combined with crops coming off early or being plowed down in some cases, makes planting a mixture of peas and oats or annual rye grass and forage turnips worthwhile for those needing grazing or forage to harvest."
Kok also reported concerns about 15 percent to 20 percent of corn stalk samples tested, tested high in nitrogen (N). That is an issue if it is fed as forage, however, the fact that 80 percent or more didn't test high, means a lot of free N was left in the field that the plant was unable to move into grain due to the drought. That nitrogen will not stay in the soil waiting for the next crop to be planted."Growers could lose up to 100 pounds of N per acre if they do nothing," said Kok. "Cover crops can sequester the N and hold it or bank it as organic matter."
Kok recommended crops like daikon radishes with oats, as they will soak up N and die out over winter, requiring no management next spring before planting. In the case of fields going into soybeans, he suggested cereal rye as it will take up a lot of N and produce lots of biomass to hold the soil. "It helps with N, reduces erosion and provides great weed control, too," said Kok. "Those with more experience with cover crops might try a mix of crimson clover, annual rye and radishes. The radishes bank the N and help with compaction. Turnips don't do as much that way; however, they provide good feed value for cattle."
Pennsylvania farmers have been early adopters of cover crops, driven in large part by fertilizer runoff concerns in the Chesapeake Bay watershed. Recognition of forage and grazing values are increasing in that livestock-heavy state. "Hairy vetch used to be our leguminous cover crop of choice, but we had some failures. Crimson clover seems to be more consistent, and the seeding rate is about half that of hairy vetch," said Sjoerd Duiker, associate professor, Soil Management and Applied Physics, Penn State University. "We've experimented with fava beans, which are likely to winter-kill, but put on a lot of biomass in the fall and as a legume can fix a lot of nitrogen.
Tillage radishes can be used after a traditional corn harvest but in drought situations, early crop removal lets you establish these cover crops that wouldn't have enough time after a normal corn harvest."
Duiker did emphasize the importance of considering herbicide carryover, especially following drought. "The chemicals may be in a fairly shallow soil layer," he said. "Crops like tillage radish and legumes can be damaged, though grass cover crops are less likely. Check rates and how sensitive your cover crop is."
Of course, the viability of cover crops assumes rain. Some cover crops, like annual ryegrass, only need a heavy dew to germinate, but without soil moisture will quickly die. Whether the cover crop is drilled into the soil or broadcast also makes a difference. Drilled seed has a much better chance of germination compared to spread or aerial applied seed. However, even non-germination in the fall doesn't signal a complete loss.
"In 2010 we didn't have nearly enough moisture to get the cover crops going, and several kinds of crops didn't come up until spring," noted Kok. "We still got some benefits with beautiful stands of cover crops before planting."
If rains do come this fall, cover crops will grow vigorously and create a good situation for planting, with the option of killing the cover crop first and planting or drilling into the cover crop and controlling it after. "Either way, the cover crop will pull excess moisture out, and the grower ends up with a better soil structure that can be driven on sooner than with no cover crop," explained Kok.
If the drought continues into 2013, cover crops can still be advantageous; however, they should be killed off early enough to not steal moisture from the next crop. Early control does sacrifice some biomass production and nitrogen fixation from legumes in a mix, noted Kok. Letting it grow opens up other opportunities for haying and grazing as noted by Duiker. Growers need to check with crop insurance agents to verify grazing or haying is allowed.
LEARNING CURVE FOR RETAILERS
Kok pointed to an inherent conflict some retailers see with cover crop promotion. "Some retailers see guys growing cover crops like clovers and other legumes as growing their own nitrogen; others see it as a great opportunity to sell cover crop seed and apply it," he said. "Some don't want to mess with the complexity of a new business and the knowledge needed."
Kok noted that some retailers are purchasing highboys and converting them to cover crop seeders. Others are taking on the role of aggregators, finding farmers who want cover crops applied and contracting for them with an aerial applicator, turning it into a turnkey operation. Making sure the seed is applied in a timely manner takes a lot of pressure off the farmer.
Duiker described new companies stepping in to fill the gap when retailers hold back. "They focus on selling cover crop seed as part of a cover crop solution," he said. "The companies are becoming pretty sophisticated, just as the growers are. Growers used to order cover crops without knowing which variety they purchased. Now they want to know what variety and where it is from. This was caused by some issues with cover crop seed we didn't know enough about. Barley from the South, for example, is often not winter hardy in Pennsylvania. Selecting a variety for the area that is winter hardy is important."
Millborn Seeds, though not new, is growing with grower interest in cover crops. Originally offering turf and forage grasses, customer demand has refocused the company on forage/cover crops. As a result, the company is growing in other ways, becoming more full service. They have added agricultural biologicals, mycorrhizal fungi and some crop protectants. Seed remains the main business; Millborn carries almost every kind of seed but corn and soybeans.
"We have around 50 different species, including brassicas, turnips, legumes as well as grasses," said Justin Fruechte, Milborn Seeds. "We can tweak blends based on what the customer needs."
Fruechte recommended planting small seeded varieties that require very little moisture to germinate when planting into dry, hard packed ground with very little residue. "Things like turnip work really well as a late season cover crop with cold tolerance and high feed quality," he said. "Millet is very drought tolerant and another small seed. Of course, it is always good to have grass in the mix, especially when grazing is planned."
Duiker, Kok and Fruechte pointed to a tremendous shortage in cover crop seed this year. Prices have already shot up, and many cover crops are in short supply with some already difficult to get. "Cereal rye seed priced at $20 per bushel this year normally sells for $9 and commonly for $7," said Duiker.
"There is already a huge deficit in cereal rye grain and triticale, as short as we've ever seen, and we haven't even hit planting time," said Fruechte. "As people start getting rain, I expect demand will jump more."
Helping growers identify the cover crops that (if available) will do them the most good given their needs will be easier if they live in Ohio, Indiana, Michigan, Minnesota, Wisconsin, and Ontario. Those states and province, soon to be joined by Iowa and Illinois, are part of a Midwest Cover Crop Council website (www.mccc.msu.edu) cover crop selector tool.
"The tool provides a county by county chart for member states with recommendations on what can be planted and when it should be planted in that county," said Tom Kaspar, USDA-ARS. "It also will say how best to take up N. For example, a legume is not as good as grass; however you may want to plant the legume if planning a corn crop following corn."
Kaspar said maintaining the biological life cycle is one more reason to plant a cover crop, adding it to nutrient banking, biomass production and soil erosion prevention. "You want a year round, diverse, microbiological population so one organism doesn't dominate," said Kaspar. "You have fewer problems with disease, better residue decomposition and an increase in earthworms. Cover crops make sense, even though it may be tough at times to make the investment.