SEASONAL CHANGES OF INORGANIC NITROGEN IN SOIL DEPENDING ON APPLICATION OF DIFFERENT FERTILIZER

In the stationary field experiment during the years 2012-2014 we monitored the impact of manure and saturation sludge application on the dynamics of inorganic nitrogen forms in the soil and on the sugar beet crop (variety Expert) and we compared it with application of solitary industrial fertilizer. The results of our experiment confirmed greater dependence of the dynamics of inorganic nitrogen forms in the soil on climate conditions during the growing season compared to its dependence on the applied fertilizers. The differences among the fertilization variants were statistically insignificant. Higher concentrations of inorganic nitrogen were present in the first half of vegetation period. Manure and saturation sludge application enhanced the utilization of nutrients available from soil, which resulted in substantially higher sugar beet crop in variants where this substance had been applied. Moreover, saturation sludge increased the yield by about 12 t.ha(-1) compared with DASA; it has also proved to be an important ameliorating means improving the soil pH.