Ready your farm for cover crops this fall
Act now if you plan to use cover crops this fall to capture and recycle manure nutrients.
Some say cover crops are a relic of the horse-and-buggy days of agriculture. But a well-established cover crop can turn nutrients into cash by tying up precious nitrogen until next season.
This is especially true in fields that receive manure applications from now through fall. Roots and top growth from cover crops soak up manure nutrients until they can be recycled. Early planning and choosing wisely will help you get the most out of your cover crops.
Cover crop seed needs to be ordered ahead of time if you are not using your own seed. Figure how many acres are needed to utilize all manure nutrients in the coming months. Order seed and be ready to go when the time is right this fall.
Oats are sometimes used as a cover crop in the fall and need to be planted soon after silage harvest. Drilling oats improves germination and growth before frost. Oats that have 8 to 10 weeks of growth under their belt before a killing frost can retain up to 75 pounds of nitrogen per acre. Because oats winter-kill they are not a problem in the spring for no till or minimum tillage systems.
Choose the right crop
Another cover crop that is excellent at recycling nitrogen is oilseed radish. When planted before Sept. 1, this crop can recycle 60 to 75 pounds of nitrogen per acre and reduce winter annual weeds. Oilseed radish winter-kills in Michigan and is easy to manage in the spring.
Cereal rye is an excellent cool-season grass for capturing excess nitrogen. Because rye overwinters it can hold 25 to 50 pounds of nitrogen in the spring. It germinates at temperatures as low as 34 degrees so can be seeded later than oats, but less nitrogen will be recycled the later the rye is seeded. It will grow later in the fall and begin growth earlier in the spring than wheat. It will also provide excellent winter pasture or a green-chop in the spring. However, its vigorous spring growth must be controlled with herbicides or tillage before dries out the soil. Rye that is 9- to 12-inches tall can be controlled with 1 quart of glyphosate with ammonium sulfate per acre in the spring.
Harvested silage fields will benefit from spreading rye or wheat with a bulk spreader either just before or just after the manure is applied, and then using a shallow tillage tool to incorporate both the manure and cover crop seed. Rye and wheat are fairly forgiving of seeding depth, especially when cover, not yield, is the goal. Wheat, oats and rye should all be seeded at about 2 bushels per acre.
Slurry seeding, or adding cover crop seed directly into the manure tank and then applying with a low disturbance tillage tool has shown excellent success in establishing cover crops at MSU.
Remember, cover-crop seedings do not have to be perfect. Nutrient recovery and environmental protection—not high yields—are the goals. For more information on cover crops and slurry seeding, visit www.animalagteam.msu.edu or www.covercrops.msu.edu