Crested Wheatgrass Yields as Influenced by Water Conservation Practices 1

Abstract Evaporation of water Irom the soil surface is a major economic loss to the western United States, because water is the primary limiting factor in plant growth on arid and semiarid rangelands. ‘Nordan’ crested wheatgrass ( Agropyron desertorum (Fisch. ex Link) Schult.) planted in rows 1.1 m apart; the effect on total herbage yield of a gravel mulch, a sheet metal “mulch,” close rows of grass, and cereal grain seeded between the grass rows was determined for a 2‐year period. Some treatments received different rates of N fertilizer. Sheet metal between the rows, covering 86% of the land surface, increased mean 2‐year yield about 112% over clean cultivation (check). A gravel mulch 1.5 cm deep increased mean yield about 16%. Close rows of grass and cereal grain between the grass rows also increased total yield. Benefit from nitrogen at 22, 44, or 66 kg/ha per year was minor. Benefit from the mulches was greater the second year than the first.