Forage potential of summer annual grain legumes in the southern Great Plains

Authors: BAATH, GURJINDER - Oklahoma State University; Northup, Brian; ROCATELI, ALEX - Oklahoma State University; Gowda, Prasanna; Neel, James

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/6/2018
Publication Date: 9/27/2018
Citation: Baath, G.S., Northup, B.K., Rocateli, A.C., Gowda, P.H., Neel, J.P. 2018. Forage potential of summer annual grain legumes in the southern Great Plains. Agronomy Journal. 110(6):1-13. https://doi:10.2134/agronj2017.12.0726.
DOI: https://doi.org/10.2134/agronj2017.12.0726

Interpretive Summary: Producers in the U.S. southern Great Plains (SGP) rely on winter wheat as cool-season pasture and different types of perennial warm-season grasses for summer grazing by yearling cattle. This forage combination has been used for cattle production for many decades and has been effective. However, there are times when high quality forage is not available. The perennial warm-season grasses do not provide high quality forage during mid to late-summer, which limits yearling stocker cattle from maintaining high rates of growth. This shortage has resulted in in a continual search by researchers for plant materials that can provide forage high in nitrogen and digestibility during August through September. There are a range of annual grasses and legumes that are grown for grain in Africa, India, South and Central America that may have the capacity to serve as late-summer high quality pasture or hays in the SGP. However, any plant selection must account for their function in response to the unpredictable summer rainfall patterns and frequent occurrence of drought in the SGP. Also, any selection should not create water deficits for following crops of winter wheat, which is the main forage and grain crop for the region. Considering these factors, the selection of warm season crops with low water demands seems appropriate. This article summarizes some grain crops that may be capable of serving as forage for late-summer grazing. Bringing these crops into stocker production systems could improve the overall effectiveness of the farms by providing new alternative forage and grain crops. As such, there is a need to test whether they are adapted to growing conditions of the SGP, and to define how they respond to basic management practices.

Technical Abstract: Winter wheat (Triticum aestivum L.) and perennial warm-season grasses are the primary forage resources for grazing cattle in the U.S. southern Great Plains (SGP). However, poor forage quality of perennial warm-season grasses during mid to late-summer is a limiting factor for maintaining high rates of growth by stocker cattle. In response, there has been a continual search for plant materials with the potential to provide forage high in nitrogen and digestibility during August through September. A broad range of potential grass and legume species that are grown as grain crops in Africa, India, South and Central America may have some capacity to serve as high quality pasture or hays in the SGP. However, any plant selection should account for limitations that can be generated by unpredictable summer rainfall patterns and frequent occurrence of prolonged drought. Further, any selection should not create water deficits for following crops of winter wheat, the primary forage and grain crop in the region. Considering these factors, the selection of warm season crops with low water demands seems appropriate for the SGP. This article summarizes some grain crops that may have capacity to serve as forage for late-summer grazing. Bringing these crops into forage-stocker systems of production could improve the overall effectiveness of the agro-ecosystem. However, there is a need to investigate their adaptability to growing conditions in the SGP, and to define effects of basic management practices on forage production and quality.