SEEDING INDIAN RICEGRASS IN AN ARID ENVIRONMENT IN THE GREAT-BASIN

Indian ricegrass [Oryzopsis hymenoides (R. & S.) Ricker] is a valuable forage species adapted to arid rangelands in temperate deserts. The p urpose of this study was to test the influence of seeding date, depth, and rate on Indian ricegrass emergence and seedling establishment of acid scarified and intact caryopses (seeds). The seeding experiments w ere conducted on a wind eroding sand sheet of Lahontan age in western Nevada. During the initial year of planting, seeds of the cultivars Ne zpar and Paloma Indian ricegrass were successfully established without pretreatment by acid scarification. Acid scarified seeds did not resu lt in the established seedling stands in the field. Initial seedings w ere done in a season with prolonged moisture events with total precipi tation about twice the average. Seedling stands of crested wheatgrass [Agropyron desertorum (Fisch.) ex Link Schult] as well as other exotic and native herbaceous and woody species were established during the f irst year. During the next 4 years crested wheatgrass seedlings were n ever again established. Indian ricegrass seedlings were established in 3 of the 4 subsequent years of seeding trials using a seeding rate of 0.8 seeds/cm of row and a seeding depth of 1 cm. Indian ricegrass see dling emergence was increased by either increasing the planting depth to 5 cm or by reducing the seeding rate to 0.03 seeds/cm of row. The u ltra-low seeding rate resulted in a significant saving in seed cost.