Stand Age, Precipitation, and Temperature Effects on Forage Yield

The effects of seasonal distribution of precipitation on forage yield are often confounded by stand age. Forage yields of Russian wildrye (Psathyrostachys junceus), green needlegrass (Stipa viridula), crested wheatgrass (Agropyron desertorum), and intermediate-pubescent wheatgrass (Agropyron intermedium-trichophorum) were determined from 6 separate studies, each of 6 years duration, from 4 locations in the northern Great Plains. Stepwise multiple regression showed that forage yield of all 4 species was significantly (P<0.01) related with April and May precipitation and stand age. Forage yield of Russian wildrye was significantly (P