Cover crops for grazing is one of the quickest ways to restore soil health. A diverse blend of species can be used, and then having the animals harvest the plant production and return it in the form of manure and urine is huge for the soil biology. This is assuming plants will grow in the soil and the animals do not leave the field, like to bed down in the yard or a bush. Grazing cover crops can be grazed in a few ways, just like perennial pastures. Continuous, rotational, stockpiled, swath graze, and cut and graze are some of the options. They can be grown for insurance, to replace or supplement existing pasture, or a way to allow livestock on land that has never had livestock on it. It can create flexibility, allowing perennial pastures to receive adequate rest during stress periods of growth, provide high quality grazing for young animals or animals that require improved body conditions. By allowing perennial pastures to rest will improve long term stand health and increase productivity. Grazing cover crops can get more complex due to regrowth considerations. Species with a low growing point, good regrowth, and good palatability are some of the characteristics to be considered. For instance, corn does not have great regrowth when grazed after the fifth leaf, where Japanese millet will tolerate grazing throughout it vegetative stages. Winter cereals make a good choice when making a grazing blend when spring seeded. Oats is normally preferred over barley or wheat because it normally regrows better. Annual ryegrass is another good grass to use, but it needs to be grazed fairly hard so it does not go to seed. When it goes to flower, the stem becomes wiry and not very palatable. Italian and perennial ryegrass or Festulolium would be another choice as they would stay vegetative longer. Teff is currently being evaluated. For broadleaf plants, species from the Brassica family, kale, radish, hybrid Brassicas, and collards produce good tonnes and high protein feed. The downside is they are low fibre so they require a high fibre source when grazing and can accumulate nitrates.
Working with other broadleaf, low fibre is still an issue. Plants like chicory, plantain, sugar beet have some good feed potential. Chicory and plantain are short lived perennials that contain high sugar contents, and are very palatable. Sunflowers would be best used in a stockpile grazing situation. Most animals are not crazy about grazing them until they start producing seed, then they are attracted to the energy and oil in the grain. It will provide good soil armour, and improve snow trap. Safflower has some potential, also as a stockpile plant. It is very drought tolerant and produces a high oil grain. Sesame has potential but is under local evaluations. Legumes are the double edged sword. They are needed to supply extra nitrogen, but some legumes have a risk of bloat. It can be managed, but care needs to be taken. Using species like Berseem clover, Persian clover, or Crimson clover will provide an annual legume source. Hairy vetch can over winter, but being a vetch should have some anti-bloat properties. Care must be taken with hairy vetch. There are reports of livestock death if there is too much seed produced and consumed.
Using peas, lentils, or chickpea will be an option for stockpiled grazing. Chickling vetch is a drought tolerant option for stockpiled grazing. Once again, watch for too much grain that is consumed as it can be deadly for livestock. The basis of planning a mix for grazing, grasses drive production, legumes fix nitrogen and broadleaf gives quality as a quick rule to follow. For most of the prairies, cereals are seeded in a pure stand at 24 to 30 seeds per square foot, clovers 20 to 40 seeds, brassicas 10 to 15, to give an idea on pure seeding rates. Blends are ratios of pure rates. A blend for rotationally grazed land, a mix of winter triticale, Persian clover, and collards could consist of 80 pounds of winter triticale, 0.6 pounds of forage collards, and 1 pound of Persian clover, giving 22 seeds per square foot of winter triticale, 2.4 seeds of collards, and 3.2 seeds of Persian clover, for a total 27.6 seeds per square foot. Mortality of small seeded crops tend to be higher than larger seeded crops, so assuming 100% germination and 0% mortality, that blend would be 79.7% winter triticale, 8.7% collards, and 11.6% clover. In reality, when accounting for seedling mortality, 85% triticale, 5% collards, and 8% clover. What is good for one farm, or one field, may not be the answer on the next. As experience is gained, more diversity may be utilized on the operation. A blend for young animals will look different than a blend for mature dry cows. To create a blend that is adequate to cut green feed or silage and then graze, aim for some species that stockpile and will have some regrowth. Species like Japanese millet, oat, barley, proso millet, annual ryegrass, teff, collards, radish, sugar beet, and kale would be a good starting point. Adding some Phacelia and plantain are viable options.
Cover cropping into standing corn for grazing or silage is an easy option. Corn has a relatively open canopy so it has the opportunity to get plants growing underneath. For glyphosate tolerant corn, glyphosate tolerant soybeans is an option to be seeded in alternating rows. Hairy vetch has shown some natural resistance to glyphosate and has been seeded successfully into corn. Another option is to seed the cover crop after the last pass of herbicide, such as annual clovers, ryegrass, red clover, or plantain. Once again, herbicide residues need to be watched to ensure it will not prevent the cover crop from establishing. Radish has been seeded into corn also, but needs to be seeded at corn tasseling so the radish does not get too mature and turn woody.
For swath grazing, quality retention is one of the driving forces. Using foxtail millets have been traditionally used. They have waxy leaves so they repel water and snow well. Since they have a low energy level if cut before they have produced seed, wildlife do not normally bother the swaths. By adding a small amount of broadleaf and legume, it will help boost the relative feed value, but needs to be something that will cure easily. Large juicy leaves add to the feed quality and protein, but they need to be dried down in the swath. To have the broadleaf and legume broadcast seeded into the swath graze crop before cutting, or just after would be a safer option. This way, the added mix will germinate and grow in between the swaths. The other option is to utilize species that are low growing like subterranean clover, plantain, or chicory in its first year.
The whole idea of grazing cover crops is to reduce work load, improve the soil, feed livestock, extend grazing period, rest existing pastures, fill in feed slumps, or introduce livestock grazing into grain land.