Microbial Transformations of Nitrogen in Texas Strip Mine Spoil
Abstract
Strip mining of lignite in Texas will result in the disturbance of more than one million acres of land. The microbial component of the soil is an important consideration in attempting to return these disturbed land to pre-mining productivity, especially in relation to the cyclic transformations of nitrogen mediated by soil microbes. A study was conducted in which microorganisms in mine spoil samples from two different mining areas in Texas were enumerated, including aerobic heterotrophic bacteria, fungi, and actinomycetes, as well as nitrifiers, denitrifiers, and free-living nitrogen fixing bacteria. Numbers of these organisms were determined in undisturbed soils adjacent to the sites sampled as well as in the mine spoil. Specific studies were conducted to determine the potential for associative and symbiotic nitrogen fixation on these sites. These included an enrichment study in which glucose and lime amendments were used, and a study of unamended rates of fixation occurring in grass and legume root-soil cores. Results indicated that mine spoils are recolonized by microorganisms soon after vegetation becomes established, but populations are altered from the native condition. In non-vegetated areas numbers of microorganisms are diminished. Autotrophic nitrifiers were adversely affected by low pH, as were associative nitrogen fixing bacteria. increased utilization of legumes in reclamation programs would be beneficial to the reclamation process.
Description
Program year: 1980-1981Digitized from print original stored in HDR
Citation
McKinnon, Leslie K. (1981). Microbial Transformations of Nitrogen in Texas Strip Mine Spoil. University Undergraduate Fellows. Available electronically from https : / /hdl .handle .net /1969 .1 /CAPSTONE -McKinnonL _1981.