Selecting forage cover crops for prevent plant acres
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 for when cover crops may be hayed or grazed from Nov. 1 to Sept. 1 has opened up a window for livestock producers to produce high quality forage. There are numerous factors to consider, but before making any 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.
Although seed availability may be a challenge this year given the large number of prevented planting acres, many different species can produce forage.
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 are not frost-tolerant and will 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 rye.
Legumes (peas, clovers, etc.)
• 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.
It is important to check the field’s herbicide application history as rotational restrictions may not allow the planting of certain species for grazing or haying. For a helpful summary, see https://z.umn.edu/herbrotationrestrictions, but check herbicide labels for the most up-to-date information.
Many cover crop options can be turned into suitable forage so select species or mixtures that fit your farming operation. Before mechanically harvesting any species for dry hay or silage, evaluate moisture content to ensure forage will store effectively. Spoiled forage will easily negate the value of this forage production opportunity.