Efekti dugotrajnog zaoravanja žetvenih ostataka na prinos pšenice i agrohemijska svojstva zemljišta

The issue of plowing of crop residues has been particularly pronounced in recent decades due to insufficient use of manure, and frequent burning or removal of crop residues (CR) from the fields. The aim of the research was to examine the effect of long-term plowing of CR of corn, soybean and wheat, in combination with increasing N-doses on the wheat grain yield (GY); as well as the influence on changes in basic soil properties. On average for all variants of N-fertilization and three wheat varieties, GY obtained in the treatment with plowing of CR was by 640 kg ha-1 (i.e. 9%) higher compared to the average of the variants of fertilization in the treatment without plowing of CR. In the case of NS Obala variety, the average GY when plowing CR was by 8.7% higher, in NS Igra by 9.8%, and in NS Epoha variety by 8.9% higher compared to the treatment without plowing of CR. Based on the regression analysis, it was determined that the NS Igra and Obala varieties reacted much better to the application of increasing amounts of nitrogen at plowing of CR compared to NS Epoha. In the average of all varieties, in the treatment with plowing of CR, the regression averaged maximum GY could be achieved by applying 123 kg N ha-1 ; while in the treatment without plowing of CR, a higher amount of N was needed for a significantly lower maximum yield. The potential level of yield on the variants without plowing of CR was significantly lower compared to the variants of the trial where the CR of crops in the rotation were incorporated for a longer period of time, where even increased amounts of N could not significantly affect the increase in yield. Based on a comparative analysis of soil properties in the trial at its establishment (1971) and in 2020, it can be concluded that long-term plowing of CR with the simultaneous application of N-fertilizers did not affect significant changes in the content of humus and total N; which can be considered a positive effect; considering the significant reduction of humus content in our soils, which was determined by numerous authors.