Nitrogen transformations in a desert grassland soil

TitleNitrogen transformations in a desert grassland soil
Publication TypeThesis
Year of Publication1970
AuthorsWoods DEugene
Number of Pages50
Date Published1970
UniversityNew Mexico State University
CityLas Cruces, New Mexico
Thesis TypeM.S. Thesispp
Call Number00417
Keywordsbiochemistry,nitrogen, dissertation, dissertations, metabolism, soil nitrogen, microbial transformation, soil nitrogen, nitrogen immobilization, nitrogen mineralization, soil, biochemistry, theses, thesis
AbstractNitrogen mineralization and immobilization in a desert soil were investigated. Soils were amended with protein, protein plus glucose, or ammonium chloride plus glucose, and changes occurring in the nitrogenous substrates were noted. The primary end product of nitrogen mineralization was found to be ammonia. Amino acid-nitrogen was detected in small quantities in all three soil treatments, and the formation of free amino acids in soil appears to be correlated with microbial activity. At no time during the investigations was nitrate or nitrite-nitrogen detected. Indications were that protein was degraded to amino acids which were immediately deaminated, releasing ammonia to be either used in microbial biosynthesis, absorbed by the soil complex, or to diffuse out of the soil into the atmosphere. It appeared that the largest part of the protein-nitrogen was lost from the soil as volatile ammonia, and reasons for this are discussed. A cultivated plant, Phaseolus vulgaris L., was studied to determine the nitrogen source assimilated most readily. This was found to be nitrate-nitrogen and could be substituted by amino acids in this plant.