By James Rogers, Forage crops production specialist

NDSU Extension

I am often asked, “Can I graze cover crops?” The answer is yes, you can.

Sometimes a label we give something pigeonholes it for a specific purpose, making it difficult to think about its use in other ways. When cover crops became a hot topic a few years ago, I tried to relabel them as “forage-covers” because they are multiuse crops — they provide ecosystem services, feed and forage to livestock. The term forage-covers never took off. I guess it doesn’t have the same ring as cover crops.

There are considerations for grazing cover crops to keep in mind. In the northern Great Plains, the vast majority of cover crop species are spring cereals (cool-season annuals) such as oats, barley, wheat and triticale. Spring cereals do not require a vernalization period for flowering, meaning they grow rapidly from vegetative to reproductive. If planted in May, the grazing period for the spring annuals might last 30-45 days, ending in late June to early July. This amount of available grazing may work fine if you want to rest perennial pasturelands before turnout. Forage quality of spring cereal crops is high and will suit livestock with high nutritional requirements, such as first-calf heifers. This contrasts with southern regions, where winter cereals are planted and can be grazed for as long as six months due to their longer vegetative period.

You have a couple of options for extending the grazing period beyond early spring. To the spring cereal, you can add a warm-season annual grass, such as a millet or sorghum-sudangrass. The idea is that the warm-season grass will fill in behind the spring cereal. This might require removing livestock from the pasture after the spring cereal has been grazed to allow for the warm-season crop to develop.

Another option would be to establish an area early to a cool-season crop and another area later to a warm-season crop. This staging of crops can increase total forage production and facilitate an easy transition between forage sources. Another option to add additional grazing days would be to plant a mixture. Barley is the earliest maturing of the cool-season crops mentioned above, triticale is the latest and oats fall in between. Blending a combination can help stretch the grazing period. Other species can also be added depending on your goals. For example, adding a tap-rooted crop can add diversity and improve soil health. Legumes can also be added to improve nitrogen fixation and forage quality.

Another question I hear is, “I want to add a legume, so I don’t have to apply nitrogen fertilizer, right?” That’s a good reason, so how does that work? It works by the legume plant forming a symbiotic relationship with rhizobia bacteria. Symbiotic relationships function by each organism in the relationship receiving benefits from the other. The legume plant provides food in the form of carbohydrates to the rhizobia bacteria living in specialized plant root nodules. In return, the rhizobia bacteria fix atmospheric nitrogen into ammonia, which the plant then takes and uses.

The amount of nitrogen fixed by a legume varies by many factors, such as species, whether it is grown as a monoculture or mixture, length of the growing season, yield, environmental conditions, soil-available nitrogen and soil pH. In general, the ability to fix nitrogen is highest in perennial legumes, then cool-season annual legumes, then summer annual legumes. Nitrogen fixation is higher when the legume is grown as a monoculture than in a mixture. For legumes to fix nitrogen, it takes energy. If there is ample inorganic nitrogen in the soil, the legume will happily use this source of nitrogen rather than fix its own.

Legumes do have the ability, when conditions are right, to fix large amounts of nitrogen, no doubt about that. To capture the most of that fixed nitrogen, the legume should be cycled back into the soil through plant decay or by grazing and cycling through the animal and back to the soil. When legumes are harvested as hay and removed from the field, the majority of the nitrogen fixed by the plant moves with the bale.

This is a pretty big topic, so look for more about the transfer of nitrogen from legumes to other plants in next month’s edition of Forage Matters. 

(James Rogers is a North Dakota State University Extension forage crops production specialist at the North Central Research Extension Center near Minot, North Dakota.)

NDSU Agriculture Communication – April 30, 2026

Source: James Rogers, 701-857-7682, james.rogers.1@ndsu.edu

Editor: Dominic Erickson, 701-231-5546, dominic.erickson@ndsu.edu