The Benefits of Cover Cropping in Agricultural Production Systems

Cover cropping was commonly used in the first half of the 20th century. However, the advent of selective pre- and post-emergent herbicides in the 1950s caused many farmers to transition away from growing cover crops. Recently, the focus on soil quality and reducing chemical inputs has led to a renewed interest in the potential benefits of reintroducing cover crops into agricultural production systems.

Cover crops can be broadly defined as any non-cash crop grown in addition to the primary cash crop. These crops have the potential to increase soil organic matter and fertility, reduce erosion, improve soil structure, promote water infiltration, and limit pest and disease outbreaks. There are numerous benefits to cover cropping, though, as with any management technique, there are tradeoffs and limitations that must be considered. In many situations cover cropping can lead to a decreased reliance on fossil fuels and improved agricultural productivity.

Implementing cover crops in a crop management regime can provide numerous benefits, such as slowing erosion, improving soil health, enhancing water infiltration, smothering weeds, controlling pests and diseases, and increasing biodiversity. For organic farmers or those who do not rely on chemical fertilizers, a common reason for growing cover crops is to add nitrogen to the soil. Leguminous cover crops can provide a substantial amount of nitrogen, which crops planted after a cover crop can more readily utilize. In conventional farming systems, cover crops may be used to increase soil organic matter and improve the physical structure of the soil. Farmers may choose rapidly growing grasses or species with extensive root systems as a cover crop in these situations. Success in a cover crop management program is contingent on determining the objectives and function of a chosen cover crop. Site specification, timing, and cropping history are all factors that must be considered when selecting the most appropriate cover crop species to introduce into a system.

While there is literature supporting the benefits of introducing cover crops into a system, there are also challenges that growers may face during implementation or management. In arid or drought-prone environments, the water needs of cover crops may cause a reduction in the amount available to the main crop, or require the use of supplemental irrigation. In these situations, it is important to carefully consider if the expected benefits of cover cropping warrant the investment.

In addition to potential increases in irrigation, there are other economic costs that must be taken into account, such as expenditures for seed and soil preparations, as well as labor requirements that will change with the introduction of a cover crop. Since cover crops are left in the field, there is no direct profit to the farmer for harvested crop products. While they can reduce the impact of specific pests and pathogens, some cover crops may act as reservoirs for other insects, rodents, weeds, or diseases. If improperly selected or managed, some cover crops can persist as weeds when the field is transitioned and prepared for subsequent plantings.