Annual forage impacts on dryland wheat farming in the Great Plains

Authors: CARR, PATRICK - Montana State University; BELL, JOURDAN - Texas A&M University; BOSS, DARRIN - Montana State University; DELAUNE, PAUL - Texas A&M University; EBERLY, JED - Montana State University; EDWARDS, LAUREN - South Dakota State University; FRYER, HEATHER - Montana State University; GRAHAM, CHRISTOPHER - South Dakota State University; HOLMAN, JOHN - Kansas State University; ISLAM, M. - University Of Wyoming; Liebig, Mark; MILLER, PERRY - Montana State University; OBOUR, AUGUSTINE - Kansas State University; XUE, QINGWU - Texas A&M University

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/2020
Publication Date: 11/2/2020
Citation: Carr, P.M., Bell, J.M., Boss, D.L., DeLaune, P., Eberly, J.O., Edwards, L., Fryer, H., Graham, C., Holman, J., Islam, M.A., Liebig, M.A., Miller, P.R., Obour, A., Xue, Q. 2020. Annual forage impacts on dryland wheat farming in the Great Plains. Agronomy Journal. 113:1-25. https://doi.org/10.1002/agj2.20513.
DOI: https://doi.org/10.1002/agj2.20513

Interpretive Summary: Alternating wheat with summer fallow is a common dryland grain production system in the U.S. Great Plains (USGP). Replacing summer fallow with annual forage crops could reduce negative environmental and economic effects, but it can reduce wheat yield where water is scarce. Better understanding these tradeoffs can guide the use of annual forages in the USGP. Therefore, previous research was reviewed to determine the benefits and challenges of growing annual forages in dryland wheat systems in the USGP. The review found: 1) several forages can be grown across the region; 2) forage production is less risky than grain and seed crop production under predicted climate-change; 3) grazing may be better than mechanically harvesting annual forages, 4) Lack of infrastructure and local markets impede the use of annual forages; and (5) more networking between researchers could advance use of annual forages in the USGP. These findings are useful to producers and researchers interested in including annual forages in dryland wheat systems. The findings are also useful for prioritizing and coordinating future research activities.

Technical Abstract: Wheat (Triticum spp.) dominates dryland grain crop production in the U.S. Great Plains and other regions with semi-arid steppe climates. A common practice is to alternate winter or spring wheat with summer fallow, despite economic inefficiencies and environmental degradation. Replacing summer fallow with non-cereal grain and seed crops often reduces future wheat yields due to increased water stress during grain fill. The use of annual forages may not have the disadvantages associated with grain and seed crops. The objective of this review was to determine benefits and challenges of incorporating annual forages into dryland wheat systems in the U.S. Great Plains. Results indicate that: 1) cool- and warm-season, annual grass and broadleaf species can be grown for forage across the region; 2) forage production will be less risky than grain and seed crop production under predicted climate-change scenarios; 3) grazing annual forages may offer advantages (e.g., nutrient cycling, improved soil structure, added revenue from livestock) over mechanically harvesting annual forages; 4) the lack of infrastructure and local markets impede the use of annual forages to diversify wheat-based cropping systems in the region; and (5) limited networking among researchers hinders the advancement in knowledge on how annual forages can be used to improve dryland wheat system resilience.