Anthropic impact on the formation of the amino acid fraction of nitrogen and its reserves | Impactul antropic asupra formarii fractiei aminoacidice a azotului si rezervelor sale
2015
Frunze, N., Academia de Stiinte a Moldovei, Chisinau (Republic of Moldova). Inst. de Microbiologie si Biotehnologie
New data have been obtained regarding the fractional composition of soil amino acid nitrogen and its reserves(0.45 to 1.15 t/ha) in typical chernozem (in a seven-field-rotation system with fodder crops) compared with humus reserves (0.7 to 2.16% ) and gross nitrogen (14.07 to 43.27%). The content of hydrolyzed nitrogen forms was determined (43.73 to 74.6%), as well as the contribution of individual amino acids to the formation of amino acid nitrogen (0.22 to 11.07%). The nitrogen of six amino acids(alanine, aspartic acid, glycine, arginine, glutamic acid and serine) constitutes 67% from the total nitrogen of amino acids. The rate of nine amino acids (lysine, leucine, proline, threonine, histidine, valine, isoleucine, cystine, and phenylalanine) in the formation of nitrogen reserves ranges up to 30%. Tyrozine, methionine and alpha aminobutyric acid have made the least contribution to this process. For comparison, soil samples from a forest strip (natural biocenosis) were also analyzed. The obtained results show the superiority of virgin soil in the formation of amino acid nitrogen (1.6 t/ha), as compared witn arable soils (0,45-1,14 t/ha). Structural changes in the latter ones could be characterized by analogy with the modifications in the structure of microbial communities, which are usually observed in the case of situations that are considered as stressful.
显示更多 [+] 显示较少 [-]