Chemical and physical properties of lignite spoil material and their influence upon successful reclamation

Abstract

A three year forage crop study was initiated in 1975 at the Big Brown mine in Freestone County, Texas, to determine the yield and reclamation potentials of various grasses and legumes on a lignite mined soil. Grasses used in the study included NK-37 bermudagrass, Coastal bermudagrass, Kleingrass, Coastal bermudagrass, and Yuchi arrowleaf clover proved to be the most productive species of the forages tested. Statistical analyses demonstrated that nitrogen was the most limiting fertilizer nutrient necessary for the production of grasses on the mined soil. Phosphorus was shown to be the most important fertilizer nutrient which must be added for adequate legume production. Nitrate-N was more effective in increasing Kleingrass production than was NH+4-N because of surface application of the nitrogen fertilizers, extremely low nitrification potentials in the mined soils, droughty soil surface conditions during summer months, and the low surface rooting density of Kleingrass. This result was also observed for Coastal bermudagrass when the nitrogen fertilization rate was less than 112 kg/ha/yr.