Annual Cover Crops an Additional Forage Source
As a result of a challenging fall harvest and a considerable precipitation deficit across much of North Dakota, ranchers are considering options to increase their forage supply.
“Recent precipitation in portions of North Dakota impacted by drought may make annual forages and cover crops viable forage options for hay production or grazing,” says Miranda Meehan, North Dakota State University Extension livestock environmental stewardship specialist.
The lack of spring precipitation in much of the state resulted in low surface soil moisture needed to support the establishment of annual forage and cover crops. Despite recent rains, available soil moisture and recommended planting dates will limit producers’ options. Forage species selected will vary based on the primary planned use: hay, fall grazing or next spring grazing.
Recommended Forage Species for Hay Production
“The best options this late in the growing season will be warm-season forages,” says Kevin Sedivec, NDSU Extension rangeland management specialist. “Foxtail millets have the shortest growing period (seed germination to heading). With drought conditions, Siberian millet will be your best option. Other options include sudangrass and sorghum-sudangrass hybrids.”
These warm-season crops should be planted no later than late July/early August. Harvest before a hard frost or directly following the hard frost to retain forage quality and palatability. Because of the shorter day length and cooler temperatures in late summer/early fall, getting sufficient dry-down to put up hay can be difficult for sorghum-sudangrass hybrids.
Recommendation for Fall/winter Grazing
Producers have many forage options to plant that can be grazed late this summer through early winter. Foxtail millet, sudangrass and sorghum-sudangrass also can be used as pasture. However, once these forages freeze, livestock tend to be more selective and increase waste through trampling.
Cool-season cover crop mixtures make excellent pasture well into the early winter period. However, cool-season plants are less water efficient and will be more prone to fail if the drought persists. Make sure ample moisture is available in the topsoil for plants to establish and grow.
A good option for a fall/winter grazing mix is a seed mixture of cool- and warm-season crops. The cool-season crops will retain nutritional quality after a freeze while the warm-season crop provides fiber for energy and proper rumen function.
Recommendation for Spring 2021 Grazing
Winter annuals can be a great option for spring grazing by helping reduce pressure on already stressed rangeland and pastures while providing cover on the soils. Winter annuals should be planted in September. Winter annuals include winter wheat, winter rye and winter triticale. Winter annuals can be utilized for early season grazing or harvested for hay.
Winter rye and triticale will be the best option for grazing in May through early June. Winter wheat produces less foliage in May and will provide a better option for hay. Winter rye and triticale can be harvested for hay by early June, while winter wheat is harvested in late June.
Many annual forages have toxicity risks when growing under stress. Cereal grains, turnips and millet can be high in nitrates when grown in droughty conditions. Do not add any nitrogen fertilizers when planting these forage crops this summer.
Test for nitrate levels, especially if plant growth occurs under drought stress. Sorghum, sudangrass and sorghum-sudangrass hybrids are susceptible to prussic acid toxicity when immature or under stress, or directly after a frost.
“We realize that producers are taking a risk in establishing an annual crop, given the dry conditions, and cost may be a factor,” Meehan says. “NDSU Extension has developed a cover crop cost calculator that provides the ability to estimate and compare the cost of different mixes.”
It can be accessed at https://tinyurl.com/NDSUCoverCropCalculator.
“Farmers may be reluctant to plant annual forages because of fear of soil moisture depletion and a desire to recharge the soil,” Sedivec says. “If the cover crop develops enough structure, it will protect the soil from erosion while providing aid in trapping snow and reducing evaporation for moisture conservation, potentially improving soil moisture for spring planting while providing forge for livestock.”
Source: North Dakota State University