The aim of research is to assess the ecological state of integrated cover soil by the degree of degradation at various doses and methods of phosphogypsum application. Research was conducted in Salsk district of Rostov region. The target of research is southern chernozem (zonal soils) and solonetz, which make up an integrated soil cover with more than 35 % solonetz content. According to the experimental scheme, the effect of phosphogypsum impact on indicator values of solonetz and zonal soils degradation (alkalinity, solonetsity, density of soil composition) was studied against sideration and subsoiling with the distribution of the accepted (overall application) and proposed (selective application) technologies of application into the soil complex. As a result, on the fifth year of complex melioration aftereffect, the southern chernozem and solonetz became undegraded (the degree of degradation was equal 0 in terms of “alkalinity”). A similar situation occurred with exchangeable sodium. According to the soil density chernozem got the status of undegraded soil while solonetz became slightly degraded. It has been proved that 5 tons/ha of phosphogypsum are sufficient to eliminate the negative properties of southern chernozem, and 10 tons/ha of phosphogypsum are necessary for solonetz. Technology with a selective ameliorant application method should be preferred by reclamation, that is, to irrigate the whole area with a phosphogypsum rate intended to displace sodium from soil absorption complex of zonal soil completely. It is determined that the content of labile forms of zinc, lead, nickel, cadmium, copper is considered the most dangerous because of their availability for plants and does not exceed the maximum permissible concentrations on the investigated soils with integrated soil cover.
Key words: complex cover, soil degradation, chernozem, solonetz, reclamation, phosphogypsum, ecological assessment.
