Forage Production and Removal from Western and Crested Wheatgrasses Under Grazing

Abstract

Forage production and removal from tillers of western wheatgrass (Agropyron smithii Rydb.) and crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult.] were studied at two stocking rates with long-interval time-lapse photography. As stocking rate increased, frequency of grazing increased markedly, but the proportion of available herbage removed at each grazing event increased only in 1977 on western wheatgrass. Forage production per tiller of western wheatgrass was usually higher under light than under heavy stocking, and in one year production of grazed tillers under light stocking was often higher than production of ungrazed tillers. Production per tiller of crested wheatgrass under grazing was marginally less than that per ungrazed tiller, with no difference between stocking rates. Patterns of forage removal with grazing were markedly different from those with clipping, and removal with grazing was much less severe than that imposed in most clipping studies reviewed.