effect of nitrogen fertilization and microbial preparations on nmin content in soil after potato harvesting

a three-year field experiment was conducted under conditions of luvic chernozem soil. diversified nitrogen fertilization with 0, 60, 120, and 180 kg n ha-1, and microbial preparations improving soil properties were applied to potatoes, cv. ‘satina’, cultivation. n–no3 concentration in the soil profile (0–0.9 m) in autumn after potato harvesting fluctuated from 28 kg n ha-1 in the n0 treatment to 70 kg n ha-1 in the n180 treatment, whereas n–nh4 content varied from 22 to 48 kg n ha-1, respectively. the level of nitrogen fertilization also had a significant effect on the change in soil n–no3 content during the autumn-winter period. the decrease in n–no3 content in the n0 treatments was 7% compared to 24% in the n180 treatments. application of microbial preparations to potato cultivation caused an increase in nmin content in soil after crop harvesting. however, after the autumn-winter period, a lower amount of n–no3, compared to the control treatment, was found in the treatments where microbial preparations had been used.