Effect of tillage and fertilization on soil Nin forms

Abstract

The aim of this study was to evaluate the effect of different tillage, fertilization, depth of soil sampling and date of sampling on dynamics of N_in forms in a Haplic Luvisol under winter wheat (Triticum aestivum L.). In the experiment three main tillage systems for winter wheat were used: B1 = conventional tillage (to 0.25 m); B2 = shallow tillage (to 0.20 m); B3 = minimization tillage (to 0.15 m). Three variants of the fertilization were used within each treatment: 0 = unfertilised control; PH = NPK fertilization; PZ = NPK fertilization + plough down of postharvest residues. The highest average concentration of inorganic nitrogen (28.68 mg kg^-1) was found in autumn period. It was result of more favourable temperature and moisture conditions in the soil and also of poor uptake by plants. Based on our results, the highest concentration of N_in was found under shallow tillage (14.07 mg kg^-1). Analysis of variance showed that only fertilization (p=0.8956) had no statistically significant effect on amount of N_in. Despite this fact, slight increase of concentration of inorganic nitrogen has been seen in the variant PZ (13.33 mg kg^-1) compared with variants PH (13.11 mg kg^-1) and 0 (13.21 mg kg^-1). On the basis of our results we can conclude that soil and climatic conditions were major factors that influenced concentration of N_in in the soil.

Keywords: ammonium nitrogen, nitrate nitrogen, tillage, fertilization, winter wheat