Effect of the Application of Rye-Grass on the Contents of Individual Amino Acids and Amino Sugars Contained in the Organic Nitrogen in Soil

Abstract

Six months after adding r4C-labelled rye-grass to sand and soil, the contents of amino acids and amino sugars in the organic nitrogen were examined. In both sand and soil, about 75 per cent of the added rye-grass r4C was mineralized as carbon dioxide and a part of the r4C added was incorporated into the amino compounds. Analytical results showed that Gly and Ala in organic nitrogen in both sand and soil were distinctly high in content, Glu, Asp and Lys were next, and Val, Thr, Ser and Leu followed, and that the amino acid compositon was not similar to that of the added rye-grass and amino sugar compounds were recognized. These facts suggest that when a plant material is decomposed in soil, its composition of amino compounds is exchanged through the microbiological metabolism and approaches what is contained in the soil natively, and that amino sugar compounds are synthesizeds newly and accumulated in soil due to their resistance to decomposition .