A Review of Livestock Grazing and Wheat Grain Yield: Boom or Bust?

Abstract

AbstractWinter wheat (Triticum aestivum L.) grown as a dual‐purpose crop is a unique and economically important resource, especially in the southern Great Plains. Since the last major review of grazing effects on grain yield, in 1956, wheat cultivars have been developed that may affect the productivity of the grazing‐grain enterprise. Thus, we decided to review current research on grazing winter wheat and the effects on grain yield in light of earlier information. During a year of favorable precipitation and adequate to excess soil fertility, tall winter wheat cultivars grazed prior to jointing experienced increased grain yield relative to nongrazed wheat, because of reduced lodging. Current research suggests that the grain yield of semidwarf wheat cultivars is more sensitive to forage removal than for tall cultivars. Grazing termination dates necessary to prevent grain yield reduction of semidwarf cultivars also appear to be much earlier than for taller wheat cultivars. The reason for the difference in grazing tolerance is not clear; however, research suggests that semidwarf cultivars require maximum leaf area at anthesis for maximum grain yield. Tall wheat cultivars are not affected in the same manner, and decreased leaf area due to later grazing does not reduce grain yield of taller wheat cultivars to the same extent as for the semidwarf cultivars. Thus, taller wheat cultivars have the potential for extending the grazing period for livestock producers while producing grain yield similar to that of semidwarf wheat cultivars (which generally produce more grain in a nongrazed situation).