EFFECTIVENESS OF DIFFERENT FERTILIZER SYSTEMS’ LONG-TERM APPLICATION IN THE CROP ROTATION

The purpose of the work is to study the effect of various fertilizer systems in the crop rotation of a long-term agrochemical station on the yield of cultivated crops in the conditions of the Primorsky Region. This paper summarizes the results of nine rotations of a long-term stationary field experiment established in 1941 on bleached meadow-brown heavy loamy soil based on a nine-field crop rotation. The use of different fertilizer systems during nine rotations of crop rotation increased the yield of agricultural crops, in comparison with the control variant without fertilizers, on average for the experimental variants, by 23.1–25.8 %. At the same time, soybean and spring wheat react differently to long-term fertilization. It was established that spring wheat, on average for nine rotations, formed the highest yield of 23.6 c/ha on the mineral system with a double dose of NPK, the increase to the control was 38.0 %. The highest soybean yield (of 18.2 q/ha) on average over the period of research, was obtained on a complex fertilizer system with a double dose of NPK, an increase to the control was 15.9 %. As a result of many years of research, it was found that in the variant without fertilizers, the crop rotation productivity was in the range of 10.9–31.9 c/ha of grains units. Studies have shown that productivity increased with each successive rotation. This became possible due to the observance of crop rotation, the supply of organic matter with root and crop residues of cultivated crops, the presence in the crop rotation of perennial grasses used as green manure fertilizer and the use of new more productive varieties.