By Sarah Hirsh and Haley Sater et.al
Cover crops can provide various benefits, such as building soil organic matter, scavenging nutrients, or controlling pests such as weeds. Maryland already leads the nation in having the highest percent of farmland practicing cover cropping (USDA ERS). The Maryland Department of Agriculture’s (MDA) cost share program recorded over 450,000 acres of cover crops during the 2023–2024 season. However, since cover crops are not a primary source of farm income, we tend to spend less time planning and managing them when compared to cash crops. Cover crops may be perceived as a one-size-fits-all bridge between the cash crops, with the same cover crop used regardless of other system factors. However, all cover crops are not equal, and different cover crops can be used for different purposes. Cover crops will be more beneficial if we tailor them to achieve a primary purpose or goal, and to fit best within the cash crop rotation. In addition, we need to be realistic about how the cover crop is likely to perform, given restraints such as the length of growing season, and the capabilities of the farm operation to manage the cover crop. Cover crop planning can greatly increase the benefits that cover crops provide, making the overall farming system more productive, sustainable and profitable.
Project partners (University of Maryland Extension, Future Harvest, Million Acre Challenge, Sustainable Chesapeake, Maryland Department of Agriculture, and Colorado State Institute for Research in the Social Sciences) worked with farmers on the Eastern Shore of Maryland to plan and implement site-specific, purposeful cover crops. We recruited and planned cover crops with 12 farmers in year one, 21 farmers in year two, and 17 farmers in year three. The farms included all nine counties on the Eastern Shore of Maryland. Farmers participated from one to three years of the project. We developed a cover crop planning protocol, during which farmers identified the top needs of the field that can be addressed through cover cropping, identified and/or created gaps in the cash crop rotation to fit cover crops, and critically evaluated the limitations of cover crops. We encouraged farmers to consider these three factors together when planning cover crops, since they are inter-related.
For example, cover crop selection and management would vary based on the length of the growing season and the subsequent cash crop. For example, a legume cover crop would be more valuable to a subsequent corn crop than a subsequent soybean crop. The crop rotation may also need to be modified to allow for a long enough cover crop growing season to accomplish a particular goal (Figure 2). See the published factsheet: https://extension.umd.edu/resource/cover-crop-planning-fs-2024-0743/ for more details.