Influence of organo-mineral fertilizers on the basis of the precipitation of sewage on micromycetes cenosis

Abstract

One from actual problems of ecological safety of the modern industrial cities development is utilization of sewage. One of solutions of this problem is studying of possibility of use of ecologically safe organo-mineral fertilizers on the basis of a precipitation of city sewage. Therefore studying of influence of organo-mineral fertilizers on the basis of a precipitation of sewage (Dnipropetrovsk) in comparison with complex fertilizer ammophos on the number and specific structure of soil micromycetes was the purpose of researches. Field experiments were made on sites of 5 m2 in the following variants: control without fertilizers; introduction of ammophos and organo-mineral fertilizers on the basis of a precipitation of city sewage in number of 10 and 30 t/hectare. Experiments were made in triple frequency on fields of Erastovsky experimental station of Institute of agriculture of steppe zone NAAS of Ukraine (Pyatikhatsky area, Dnipropetrovsk region). The soil (chernozem usual) selected from depth of 0–10, 10–20 and 20–30 cm under crops of summer barley of a sort «Galaxies» in a phase of full maturing of seeds. Quantity of soil micromycetes considered on Capek agarized medium. Structure of soil microscopic fungi cenosis estimated using indicators of frequency of species occurrence, similarity of communities (Serensen coefficient), extents of species domination in cenosis (Berger-Parker index), specific wealth (Simson index) and a specific variety (Shannon index). In a layer of soil 0–10 cm of a site at introduction of 30 t/hectare of organo-mineral fertilizers on the basis of a precipitation of city sewage the quantity of microscopic fungi increased by 1.5 times in comparison with control. In the bottom layers (10–20 and 20-30 cm) – in 1.3 and 1.6 times –espectively. The increase in quantity of micromycetes is noted and in the soil of sites after introduction of 30 t/hectare of ammophos. In a layer of soil 0–10 cm their number increased by 2.3 times, and in the bottom layers – in 1.9 and 2.1 times respectively in comparison with control. From soils of a site of a field experiment are allocated and identified 13 species from 10 genuses of microscopic fungi. Soils of sites of various variants of experience differed on the frequency of occurrence of microscopic fungi. From the chernozem usual of control site are allocated 4 species of micromycetes. In micocenosis dominated Fusarium oxysporum with a frequency of occurrence 100 %, to subdominant species (frequency of occurrence 40 %) belonged F. solani. The least similar on the control was micocenosis of site at introduction of 30 t/hectare of ammophos. Micocenosis of soils in variants of experience at introduction of ammophos in number of 10 t/hectare and organo-mineral fertilizers from a precipitation of city sewage in number of 30 t/hectare were very close to control variant. In the soil of site at introduction of organo-mineral fertilizers from a precipitation of city sewage in number of 30 t/hectare 6 species of microscopic fungi are identified. In micocenosis dominated P. vinaceum (frequency of occurrence 80 %), Trichoderma viride (frequency of occurrence 40 %) belonged to subdominants. On the basis of determination of micromycetes frequency of occurrence, coefficient similarities of communities, indexes of domination, specific wealth and variety, it is proved that entering into the soil of organo-mineral fertilizers on the basis of a precipitation of sewage promotes to increase of specific variety of microscopic fungi. It is shown that use of organo-mineral fertilizers on the basis of a precipitation of sewage considerably reduces the frequency of occurrence of a phytopathogenic specie Fusarium oxysporum which is the activator of root decay at plants.