Feed and forage: Flowering cover crops stack ecosystem services to provide multiple benefits for livestock and pollinators

Authors: GAMBEL, JESS - Oak Ridge Institute For Science And Education (ORISE); FRANCO, JOSE - Savanna Institute; French, Elizabeth; Kalscheur, Kenneth; Christensen, Rachael; PESSEREAU, ELIZA - University Of Missouri; Duff, Alison

Submitted to: Agriculture, Ecosystems & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/6/2026
Publication Date: 3/25/2026
Citation: Gambel, J., Franco, J.G., French, E.A., Kalscheur, K., Christensen, R., Pessereau, E., Duff, A. 2026. Feed and forage: Flowering cover crops stack ecosystem services to provide multiple benefits for livestock and pollinators. Agriculture, Ecosystems & Environment. https://doi.org/10.1016/j.agee.2026.110357 .
DOI: https://doi.org/10.1016/j.agee.2026.110357

Interpretive Summary: Cover crops are grown to “cover,” or protect, the soil between plantings of cash crops. Cover crops can provide multiple benefits for farms, including enhancing soil health and water infiltration, reducing soil erosion and weed growth, and attracting beneficial insects such as predators of crop pests. When farms use flowering cover crops and allow these crops to grow long enough to bloom, cover crops can provide food resources (i.e., nectar and pollen) to pollinating insects such as bees, butterflies, wasps, or flies. For farms with livestock, cover crops can also be harvested to include in diets fed to beef or dairy cattle. Can the same flowering cover crops be used to provide adequate resources for visiting pollinators as well as quality feed for cattle? To answer this question, we assessed flowering, insect visitation, and potential added energy provided to dairy and beef cattle diets for one winter cover crop, camelina, and two summer cover crops, buckwheat and sunflower. Peak flowering and insect visitation occurred in mid-May for camelina, in mid to late-July for buckwheat, and in mid-August for sunflower. All three crops had mostly non-bee visitors (e.g., flies); in terms of bees, camelina and sunflower had the most visits from large dark bees while buckwheat had the most visits from small dark bees. When harvested through peak flowering, camelina added to cattle diets increased energy intake for dairy cattle but reduced energy intake for beef cattle. Buckwheat harvested from early to peak flowering provided added energy for beef cattle while buckwheat increased energy intake for dairy cattle when harvested through all flowering stages. Similarly, diets with sunflower increased energy intake for dairy cattle when harvested through all flowering stages and provided added energy for most beef cattle when harvested through peak flowering. Finally, camelina diets decreased milk yield of lactating cows but buckwheat and sunflower diets increased yield when harvested during any flowering stage. The results from these case studies demonstrate that flowering cover crops can be used for a range of functions including providing forage for insect pollinators and feed for cattle.

Technical Abstract: Cover crops provide multifunctional benefits for agroecosystems. For pollinators, cover crops can provide valuable forage depending on the resource availability in the greater landscape during the growing season. An additional potential benefit to cover crops is supplying feed for livestock. Here we explore case studies of three different flowering cover crops (camelina, buckwheat, and sunflower) as options for forage for pollinators and feed for livestock. For these crops, we measured plant growth and flowering, insect visitation and visitor types, and forage yield, as well as modeled potential energy provided to dairy and beef cattle fed diets with added cover crops. For dairy cows, we modeled potential milk yields of lactating cows fed diets with cover crops added. We found that camelina flowered and had the most insect visitation early in the growing season, had mostly non-bee visitors followed by large dark and small dark bees, and provided enough energy for growth in dairy cows through peak flowering but was not adequate for providing energy for milk production in lactating cows. Buckwheat reached peak flowering and visitation mid-season, also had mostly non-bee visitors followed by small dark bees, and, unlike camelina, provided enough energy for growth in dairy and beef cattle during some flowering stages and enough energy for milk production during all plant phenological stages. Finally, sunflower reached peak flowering and visitation late in the season, also had mostly non-bee visitors followed by large dark bees and bumble bees, and provided enough energy for growth in dairy cattle as well as most beef cattle (steers and pregnant cows) during some flowering stages. Sunflower diets provided energy for milk production in lactating dairy cows during all plant phenological stages. These findings suggest the potential for flowering covers crops to provide forage resources for pollinating insects throughout the growing season and supply dairy and beef cattle with adequate energy for growth and milk production when added to traditional diets.