The aim of the research is to investigate the impact of complex land reclamation including chemical reclamation, manure applying, and ameliorative tillage on physical and chemical properties of chernozem solonetz. The study was carried out in the Rostov region at two backgrounds: 1 – ameliorative tillage by three-tier plow: 2 – ameliorative tillage by plow-milling tool. On the base of own investigations and analysis of science publications it is shown that chernozem solonetz consisting the complex with southern chernozem from 30 to 75 % needs the special reclamation considering the environment of zonal soils. Data analysis obtained by the authors during the study of different variants of complex land reclamation (chemical reclamation + applying of organic fertilizers + ameliorative tillage) has shown its impact on plow and subsurface soil layers, as well as on the fertility improvement of the whole reclaimed layer. The following combinations of phosphogypsum (PG) and manure (M) are the most effective by reclamation impact: 10 t/ha PG + 20 t/ha M and 10 t/ha PG + 40 t/ha M, followed by ameliorative tillage by plow-milling tool. In these variants to the 4th year of after-action sodicity in soil layer 0–40 cm decreased by 70 and 65 % respectively, and exchangeable sodium percentage reached 8–9 % from the sum of exchangeable cations that is almost fit to the values of zonal soil (6–7 %). Simultaneously in solonetz the alkalinity vanished and sodium persistence increased to the medium level (35 meq/100 g soil). Before the land reclamation the soils were not sodium persistent (less than 10 meq/100 g soil). The leaching of toxic salts at applying of 10 t/ha PG + 40 t/ha M reaches 53–62 %. While at the background of plow-milling tillage the salt leaching was higher by 15–35 % comparing to the three-tier plowing.
Keywords: chernozem solonetz, chemical reclamation, phosphogypsum, manure, ameliorative tillage, sodicity, alkalinity, sodium persistence.
