Change of biological activity of soils of agrocoenosis under the influence of increasing rates of mineral fertilizers application in natural conditions and in lysimeter experiments

Abstract

The peculiarities of microbiological and enzymes activity were investigated in dependence on genetic characteristics and content of organic substances in Peat soils, Organic-mineral and Soddy-podzolic loamy sand and loamy clay ones in natural and modeling conditions, as well as in the conditions of lysimeter experiments. High degree of correlation between the content of organic matter in soil and the level of activity of polyphenoloxidase, peroxidase, catalase, urease and invertase has been determined. The ratio of peroxidase and polyphenolxidase activities specifies that in the drained peat soils the processes of organic matter mineralization essentially prevail over the humification ones. Alongside with that is defined, that at the similar content of organic substances in peat soils the intensity of polyphenoloxidase, peroxidase, invertase and dehydrogenase activities were 2 times lower in peat soil developing on reeds than that on sedge one that is explained by genetic and structural peculiarities of organic substances of these soils. Obtained results allow with sufficient measure of validity to use studied biological activity data for iagnoseing change of an ecological condition of soils in connection with application of various kinds and norms of mineral fertilizers. As the most sensitive indicators, reflecting a reaction of soils on application of mineral and organic fertilizers can be considered the number and structure of microflora, enzymes activity and intensity of CO₂ producing by soil. The studied set of indicators is offered as probable and for concrete situations it can be differentiated.