Which of three summer legume forages is most water efficient?

Authors: BAATH, GURJINDER - Oklahoma State University; Gowda, Prasanna; KAKANI, VIJAYA - Oklahoma State University; ROCATELI, ALEXANDRE - Oklahoma State University; SINGH, HARDEEP - Oklahoma State University

Submitted to: Grazinglands Research Laboratory Miscellaneous Publication
Publication Type: Proceedings
Publication Acceptance Date: 2/19/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary: Abstract only

Technical Abstract: Low nutritive value of available warm-season grasses during July through September limits the production of yearling stocker cattle in the southern Great Plains (SGP). There is a broad range of potential legume species native to Africa, India, and South and Central America that are grown for grain crops may function as forages for the SGP. The region frequently encounters prolonged drought periods, and amount and occurrence of summer rainfall is highly unpredictable. The selection of low water demanding crops seems more appropriate to fit into the system, to put less stress on following winter wheat, a primary crop in SGP. Moth bean (Vigna aconitifolia), tepary bean (Phaseolus acutifolius), and guar (Cyamopsis tetragonoloba) are promising choices due to their capability of producing sufficient biomass on low precipitation. An understanding of the comparative crop response to a range of water regimes would allow better selection of crop species for the SGP. A greenhouse study evaluating these legume species under four different irrigation levels was conducted at Oklahoma State University, Stillwater, OK. The data collection includes leaf area, leaf-to-stem ratio, dry forage biomass, and physiological parameters. Results suggested that tepary bean would be the most reliable forage choice for SGP among the selected legumes, considering its greater water use efficiency and forage production under a range of water regimes.