Dynamics of nitrogen in the soil under winter wheat (Triticum aestivum L.) depending on tillage systems

Abstract

The trial on an experimental basis of Slovak University of Agriculture in Nitra during the growing seasons 2011/2012 and 2012/2013 under winter wheat was conducted. The object of this study was to determine the effects of different tillage systems on the dynamics of inorganic nitrogen forms. Three tillage systems were used: B1 -> conventional soil cultivation – medium depth ploughing (to 0.25 m); B2 -> shallow soil cultivation (to 0.20 m); B3 -> minimalization soil tillage – disk tillage (to 0.15 m). Within each treatment was used of NPK fertilization according to its content in soil + plough down of post harvest residues. Concentration of nitrate nitrogen (1.29 mg*kg-1 – 29.68 mg*kg-1) and ammonium nitrogen (0.13 mg*kg-1 – 14.34 mg*kg-1) had significant dynamics over the whole research period. The highest content of Nin was in the autumn season (39.09 mg*kg-1), which provide sufficient nutrients for initial growth of the winter wheat. Tillage system had no statistically significant effect on dynamics of inorganic nitrogen in the soil. On the other hand, reduction of depth tillage has been associated with an increase content of inorganic nitrogen (B1 = 9.54 mg*kg-1; B2 = 9.89 mg*kg-1; B3 = 11.19 mg*kg-1). The results of experiment shown that dynamics of inorganic nitrogen was mainly influenced by the change of temperature and humidity parameters during the growing season.