Heterotrophic nitrification in soils

摘要

The contribution of heterotrophic microorganisms to nitrification processes in soils of different types under natural vegetation and in agrocenoses was estimated. The intensity of heterotrophic nitrification was higher in soils of native biocenoses than in croplands. In cultivated soils, the population of autotrophic nitrifying bacteria increased. They had a dominant role in the production of nitrates (84 to 99%). The heterotrophic nitrification was more active in soddy-podzolic soil of the wood sorrel spruce forest (Pinetum oxalidosum). In the gray forest soil of the birch forest and in the virgin dark chestnut soil, heterotrophic microorganisms were responsible for the production of 33-46% of nitrates. In leached brunizems of the pine and oak forests and in soils of different-aged laylands in the forb-grass prairie, the participation of heterotrophic microorganisms in nitrification was estimated at 25%. The additional application of nitrogen fertilizers 2-5 times decreased the activity of heterotrophic organisms.