Keys to managing cover crop grazing

Integrating livestock is one of the 5 Pillars of Soil Health that has the most risk and most potential reward.

Adding livestock into your crop rotation is a great way to increase stocking rates, provide quality feed during dormant growing seasons, and positively impact soil health. Like all conservation ag practices, the integration of livestock takes proper management for success. Below are some factors to consider when integrating livestock. 

Benefits to soil health

Integrating livestock into a cropping rotation includes:

• Pasture rest. Moving livestock to a cover crop allows the pasture to rest and grow. Resting pasture not only allows above-ground forage to grow but also allows the plants to grow stronger root systems when not being grazed.
• Manure. Cattle are great at nutrient cycling. The manure and urine they deposit throughout the field are great sources of nutrients for the upcoming crop. Crop residue with high C:N ratios are much faster digested through a cattle rumen than through soil biology alone.

Field selection

The first step in success for cover crop grazing is selecting the correct crop fields for the livestock to graze on.

The ideal field will easily drain, have easy access to water, and be close to the pasture so you can pull livestock off in case of heavy rainfall. Fields that will be harvested early give the best potential for cover crop growth and extended grazing.

Corn and grain sorghum

Grazing these fields allows you to reap benefits from a cover crop, as well as the crop residue and grain remaining in the field. Fields that have been chopped for silage are great options for cover crops but be cautious of overgrazing as erosion will be more likely to occur.

Wheat

Wheat fields after harvest arguably offer the greatest potential in planting cover crops for livestock to graze. Implementing a blend of summer and winter grazing cover crops allows you to graze livestock early in the fall, then continue grazing throughout the winter and spring with proper management. 

Selecting the right cover crop to graze

Summer annual species

Many of these species have great nutrient content for grazing and their prolific growth can help suppress weeds during the late summer and early fall. For best results, plant summer cover crops a minimum of 60 days before your average frost date to give time for plenty of forage growth. If there are no platns to follow with a winter cover crop, it is important to watch the amount of residue remaining in the field to ensure good cover and reduce wind and water erosion.

Grazing livestock on a blend of plants greatly helps increase the nutritional value for the animal and reduces the possibility of toxicity and nitrate poisoning. 

• Summer legumes: Early planting is key for many legume species as they offer great forage value for livestock as well as the potential to fixate N for the upcoming crop. The forage quantity will be lower than with a grass crop, however, legumes are a great addition to blend with grass to increase nutritional value.
  • Speciies to consider:
    • Cowpeas
    • Sunn Hemp
    • Mung Beans
    • Forage Soybeans
• Brassicas: Early establishment of brassicas can produce large amounts of forage for livestock to graze in the fall. With spring growth, termination will be key to prevent seed development. Like legumes, brassicas are best suited in a mix. Grazing cattle on a field too heavily seeded in brassicas (ex. turnips or rapeseed) can cause sulfur and/or nitrate toxicity in cattle. Slowly introducing livestock to brassicas for the first week as well as providing quality trace mineral and dry hay or straw are ways to reduce the buildup of sulfur. 
  • Species to consider:
    • Turnips
    • Radishes
    • Rapeseed
    • Forage Collards
    • Mustard
    • Kale
• Grasses: Summer annual grass species offer fast growing forage for livestock feed as well as weed suppression. There are many grass species that can produce in drought conditions, offering good forage when other options have failed. With drought conditions and summer grass crops in general, it is important to time grazing to prevent prussic acid and nitrate poisoning in cattle. For green, growing forage, do not allow cattle to graze until the forage reaches a minimum of 18” tall, and prevent cattle from grazing the forage too low. It is important to prevent overgrazing of the forage as higher concentrations of prussic acid is in the lower part of the stem. As with sulfur toxicity in brassicas, gradual introduction to the forage and having hay available to cattle as well will help reduce the risk of toxicity issues.
  • Species to consider:
    • Sudan Grass
    • Millet
    • Oats

Winter hardy cover crops

Most winter hardy cover crops that are currently in use are a good fit for grazing. These crops offer over-wintering benefits and forage options in spring. This allows you to let your pastures grow so you can stockpile grass for later in the season, especially in years when hay supplies are low, and pastures are starting to green up.

While almost all cover crops offer great grazing potential, grazing does reduce the ability for cover crops to perform some of their other functions. If using rye or wheat to control weeds, overgrazing with cattle will reduce weed suppression for the summer cash crop. It is also important to allow the cover crop proper time to regrow after grazing for proper herbicide termination. Two weeks should be sufficient rest for herbicide to properly control spring cover crop growth. 

• Species to consider:
  • Clover
  • Rye
  • Triticale
  • Wheat

Proper Management

While grazing has great benefits, improper management can have a negative impact on the long-term improvement of your soil. To reduce chances of compaction, it is important to remove cattle if long periods of rainfall are in the forecast. 

Grazing cover crops has great benefits for livestock and soil. The best setup varies depending on your geographic location and goal. If you are interested in integrating livestock into your cover crop, reach out to your Cargill RegenConnect agronomist and we can work with you to develop a plan.