Grass Species Growth on a Volcanic Ash-Derived Soil Cleared of Forest

Abstract

Grasses producing high forage yields in a 20 to 28 inch precipitation zone of northeastern Oregon on volcanic ash soil (Tolo silt loam) cleared of a stagnant forest were Greenar intermediate wheatgrass, Sherman big bluegrass, and Regar bromegrass. Tall oatgrass, meadow foxtail, and creeping meadow foxtail were high yielding when fertilized. Annually fertilizing with 60 lbs. N, 10 lbs. P, and 11 lbs. S/acre increased the mean annual forage yield 1800 lbs./acre. Fertilizing increased downy brome in species not well adapted. Fertilized forage contained a slightly lower nitrogen concentration than non-fertilized forage.