Cover crops are planted for a variety of reasons — erosion control, to improve soil structure and health, to provide supplemental forage, as part of a nutrient management plan for manure application or for a combination of these reasons. Depending upon the species of cover crop planted, the crop will not be killed over the winter, but growth will resume in the spring and the grower must make some decisions regarding how to manage that crop in the spring. The management options depend upon the purpose of the cover crop. Here are some management options to consider when the goal is to utilize the crop as supplemental feed.
Cover crop management as a supplemental forage with mechanical harvest
The primary management consideration is harvest timing and harvest method. Cereal rye, triticale and winter wheat are primarily used if supplemental forage is the objective. Of these three, cereal rye quality declines the most rapidly as the plant enters the reproductive growth stage and it advances most rapidly from vegetative to reproductive growth compared to the other two forages. So the window of opportunity to make a high quality forage is narrower with cereal rye.
Generally the goal is to harvest these crops at boot to very early head stage of maturity. Because we do not get very many good drying days in our spring weather, the best harvest method is to harvest as a silage or as a wrapped forage rather than trying to get a dried forage product.
Cover crop management in a grazing system
The key to getting good utilization of these cover crops in a grazing system is to have enough animals to graze across the field before the crops get too mature and quality declines too much. So, the same comments about cereal rye apply here, the grazing window can be narrow.
The second principle that should be followed is to use strip grazing across the field giving no more than one or two days worth of grazing at a time before moving the fence to give access to another portion.
Finally be aware that grass tetany is a risk when grazing spring growth winter wheat or cereal rye so take precautions to prevent it by feeding a high Mg mineral mix.