| The usefulness of native prairie and domesticated grasses in revegetating strip mine spoil and producing biomass was examined. Experimental studies were conducted under controlled conditions to determine the response of prairie grasses to various levels of sludge amendment to strip mine spoils, and to the application of an absorbent polymer to the seeds. Various methods for establishing grasses on strip mine spoil were tested under field conditions, including amelioration with sewage sludge, and spring and fall planting times. The study site was located near Canton, Illinois on 30 year old, recontoured spoil banks.;In the greenhouse study, biomass production showed a quadratic response to increasing levels of sludge amendment to strip mine spoils. In contrast, in the growth chamber experiment there was a linear increase in biomass as the level of sludge amendment was increased up to 333 MT/ha. A major difference between these two experiments was the watering regime. Trace elements were not present in concentrations high enough to be phytotoxic.;There was no consistent pattern between biomass production and spring or fall planting times in the field study. This was probably caused by the above normal amounts of precipitation received during the two growing seasons of the study. By the end of the second growing season, Sorghastrum nutans produced more biomass than the other warm-season grasses on the unamended plots and no warm-season grasses survived on the amended treatment plots. The warm-season grasses were able to compete with weedy species on unamended sites, but not on amended sites.;The two cool-season grasses produced more biomass on amended sites than unamended sites, with Phalaris arundinacea producing more biomass than Festuca arundinacea.;This study found native warm-season grasses useful in revegetating unamended strip mine spoil. These grasses establish easily and can survive harsh environment created by strip mine spoils. |
