Skip to main content

Selecting forage cover crops for prevented plant acres

Warm-season grasses in a University of Minnesota
emergency forage trial
Jared Goplen and Liz Stahl, Extension educators

A large quantity of forage will likely be harvested from prevented plant acres in Minnesota this year, given the 2019 changes to USDA RMA’s prevented planting rules. Changing the date when cover crops may be hayed or grazed from November 1 to September 1 has opened up a window for livestock producers to produce high quality forage.

There are numerous factors, however, to consider in order to be successful. The University of Minnesota Extension has some great resources to help make these decisions and several are included below. Before making decisions, it is paramount to check with your crop insurance agent to ensure prevented planting payments are not forfeited by utilizing unapproved species or practices.

Cover crop and forage options for prevented plant acres:

Species Selection

Although seed availability can be a challenge this year given the large number of prevented planting acres, there are many different species that can produce forage for grazing, chopping, or baling for dry hay. Depending on the intended harvest method, some species will perform better than others.

Warm-season cereals (Sorghum, sorghum x sudangrass, sudangrass, and millets)

  • These species do well in hot conditions, and are best suited for July seedings.
  • Dry hay can be challenging to put up with some of these species. Select species / varieties with fine stems and seed at higher seeding rates to help with dry-down. Utilize a conditioner to help with dry-down. 
  • Sorghum or sorghum x sudangrass hybrids are often best-suited for silage or baleage due to courser stems which are difficult to dry. 
  • Prussic acid poisoning can be problematic with some species when grazed or harvested too early. Curing hay and ensiling help mitigate this risk. 
  • These grasses aren’t frost-tolerant and will likely die with temperatures near freezing. 

Cool-season cereals (Oats, wheat, barley, rye) 

  • Can be chopped or baled for dry hay in September. A cereal – pea mixture could be utilized to increase protein of silage or baleage.
  • When planted in July, cool-season cereals will likely have stunted growth due to hot conditions. Oats and barley are less heat tolerant than wheat and more likely to have decreased production. Wheat may be a better choice for July seedings. 
  • Warm summer temperatures will decrease tillering, so slightly higher seeding rates could help improve stands. 
  • Mid-July seedings will likely get to soft-dough stage for haying in early September. 
  • Winter wheat or rye may be planted for fall forage but will not begin jointing (upright growth) until next spring. Winter cereals are not suitable for mechanical forage harvesting in the fall, but will maintain higher quality for fall grazing.
  • Consider your spring termination plan if planting a winter-hardy crop such as winter wheat or winter rye. 

Legumes (peas, clovers)

  • Peas are likely the best option to include in a mix with a small grain when chopping for silage or baleage.
  • Nitrogen fixation is related to biomass production, meaning late seedings will likely not fix much nitrogen.
  • Production from late seedings will be limited, making many legumes cost-prohibitive given the higher seeding cost. 
  • Annual legumes such as peas, berseem clover, and crimson clover are subject to frost and won’t overwinter. 

Brassicas (Turnips, radish, etc.)

  • Brassica species are not suitable for hay or silage production, and should only be included in fields that will be grazed.
  • Delay planting until late July or August to avoid species setting seed. 
  • Cold-tolerant cover crops like turnips may overwinter as scattered plants or in patches if there is plenty of snow cover. 
For more information on termination strategies for over-wintering cover crops, see Spring management of cover crops.

Consider herbicide restrictions

It is also important to look back at last year’s herbicide applications to determine if certain species cannot be planted. For a helpful resource regarding the time you must wait after an herbicide application before you can plant a particular crop, visit Herbicide rotation restrictions in forage and cover crop systems from the University of Wisconsin. 

Rotational restrictions are in place, in part, to protect the food chain from any pesticide residue levels that might exceed safety standards. Be sure to check the label of any herbicides applied over the last couple of seasons for the most up-to-date information.

There are many cover crop options that can be turned into suitable forage. Select species or mixtures that fit your farming operation. Before mechanically harvesting any species for dry hay or silage, be sure to evaluate moisture content to ensure forage will store effectively. Spoiled forage will easily negate the value of this forage production opportunity.

For more information

For more information, check out these U of MN websites:

Print Friendly and PDF