Geochemical properties of chernozems in the region of nitrogen fertilizer plant, Tula oblast

In the industrial region around the nitrogen fertilizer plant "NAC Azot", Novomoskovsk and background meadows in Tula oblast were selected in August samples of chernozem (0-20 cm). In the soil contents of mineral nitrogen (Nmin) including ammonium (NH4 +) and nitrate (N-NO3-), total organic carbon and total nitrogen (Ctot and Ntot), the elements (P, Al, Ca, Mn, Fe, S, K), pH and texture were measured. NH4 +, Ctot, Ntot, Mn, Fe, S, K and the ratio Ctot / Ntot in the soil around the nitrogen fertilizer plant is not significantly different from that of the background. Significant differences were identified the soil content around the fertilizer plant in comparison with the background for Nmin, NO3-, P, Al and Ca (above 4, 1.2, 2 and 2.5 times, respectively), as well as the ratio Ntot/ Р (below 2 times ). Significant positive correlation (r) was found between the N-NO3- and Ca (r = 0.78), N-NO3- and Al (r = 0.75), Nmin and Ca (r = 0.70), Nmin and Al (r = 0.81). In soils of the industrial area was showed a trend of increasing Nmin, NO3-, P, Al and Ca, as well as a decrease in the ratio Ntot / P, indicating their acidification and less content phosphorus for plant nutrition.