Effects of Soil Materials, Mulching Treatments, and Soil Moisture on the Growth and Yield of Western Wheatgrass for Coal Mine Reclamation

Abstract

A 3-year experiment was conducted in the greenhouse at Tucson, Arizona to study the effects of three soil materials, three mulching treatments, and two soil moisture treatments on the growth and forage production of western wheatgrass (Agropyron smithii Rydb.) when used in the reclamation of coal mine spoil. The three mulching treatments were: (1) No mulch. (2) Barley (Hordeum vulgare L.) straw mulch, and (3) Russian thistle (Salsola kali L.) mulch. The two soil moisture treatments consisted of: (1) Optimum (60 cm total) and (2) Stressed (30 cm total). There were significant differences in number of stems per pot, plant height, and forage yield between soil materials, mulching treatments, and soil moisture treatments. The Gila loam soil, barley straw mulch, and optimum soil moisture treatment produced the highest number of stems per plot, the tallest plants, and the highest yield of forage. Plants were more vigorous and produced more forage when soil mulch (incorporated organic matter mulch) was used than when soils were not mulched. Barley straw and Russian thistle were of similar value as mulching materials. Within soil materials and within mulching treatments forage yields were significantly higher with optimum soil moisture than they were when moisture was limited.