Кореляційні зв’язки між показниками стану мікробного ценозу і потенційної родючості чорнозему типового

Abstract

Goal. To study the regularities of the formation of connections between separate groups of microorganisms in typical chornozem and indicators of its potential fertility for growing sunflowers with the use of different systems of basic tillage and mineral fertilization. Methods. Microbiological, laboratory-analytical, statistical. The research was carried out using soil samples from a stationary experiment on the study of short crop rotations, established in 2009 at the Panfilsk research station of the Institute of Agriculture of NAAS. Results. The number of microorganisms of many ecolotrophic, systematic, and functional groups, their physiological-biochemical activity, intensity, and orientation of mineralization processes in the soil are correlated with indicators of the potential fertility of typical chornozem. In particular, the number of ammonifiers correlates with the hydrolytic acidity of the soil (r = 0.352), the sum of the absorbed bases (r = –0.559), the content of nitrogen (r = 0.975), potassium (r = 0.739), and humus (r = 0.837). The number of CFU (colony-forming units) of mineral nitrogen immobilizers correlates with the sum of absorbed bases (r = –0.547), nitrogen content (r = 0.826), potassium (r = 0.712), and humus (r = 0.777). The number of oligonitrophils has significant correlations with saline pH (r = –0.615), hydrolytic acidity (r = 0.604), phosphorus content (r = 0.533), and humus (r = –0.586). The inverse nature of the relationship between the number of oligonitrophils and the content of humus indicates the main cause of humus mineralization — the lack of nitrogen compounds in the soil. The number of Azotobacter is correlated with the hydrolytic acidity of the soil (r = –0.539), saline pH (r = 0.568), the sum of absorbed bases (r = 0.338), the content of nitrogen (r = –0.395), and phosphorus (r = –0.470). The inverse nature of the relationship with the content of phosphorus in the soil indicates that Azotobacter is not an indicator of providing the soil with phosphorus compounds. The number of polysaccharide-synthesizing bacteria does not correlate with indicators of potential soil fertility, except for humus content (r = –0.389). Humus mineralization activity correlates with all studied indicators of potential fertility: hydrolytic acidity (r = –0.784), saline pH (r = 0.772), the sum of absorbed bases (r = 0.887), nitrogen content (r = –0.555), phosphorus (r = 0.788), potassium (r = 0.588), and humus (r = –0.760). Total biological activity is correlated with hydrolytic acidity (r = 0.363), saline pH (r = –0.343), sum of absorbed bases (r = –0.430), nitrogen content (r = 0.655), potassium (r = 0.424), and humus (r = 0.625). The total number of microorganisms correlates with hydrolytic acidity (r = 0.349), saline pH (r = –0.303), the sum of absorbed bases (r = –0.550), the content of nitrogen (r = 0.965), potassium (r = 0.735), and humus (r = 0.839). Conclusions. The analysis of correlations between indicators of the state of the microbial coenosis of microorganisms and indicators of the potential fertility of typical chornozem shows the presence of a close relationship.