The origin and nature of the soil organic nitrogen 1. amino acids

Greenfield, L. G.

Approximately 10-12% of the total soil-N which occurs in the hydrolyzable unidentified N fraction following the fractionation of soil hydrolysates by the Bremner method can be ascribed to amino acids. Revised estimates suggest that the total amino-N content of soils is approximately 50% of the total soil N. The bulk of the soil organic N evidently occurs in protein complexes. A large proportion of the N in these complexes, which can be formed in vivo and post mortem in Nature, becomes converted to acid soluble and insoluble forms during hydrolysis. A proportion of the N in these latter forms is probably the result of acid catalyzed artifact formation between the complex moieties.