Содержание и формы соединений никеля в черноземе выщелоченном Западного Предкавказья в условиях агрогенеза | THE CONTENT AND FORM OF THE NICKEL COMPOUNDS IN THE WESTERN CAUCASUS LEACHED CHERNOZEM IN TERMS OF AGROGENESIS

The article presents results of studying the total content and the forms of Nickel in the Western Caucasus leached Chernozem at three rotations of 11-fild grain-grass-arable crop rotation. The Nickel content in the soil is close to its Clark (40 mg/kg) and significantly lower than UEC (80 mg/kg). Scientifically based system for fertilizing crop rotation does not lead to the accumulation of Nickel in the soil, but creates the conditions for increasing its mobility. In the future, we may experience the need of the inclusion of Nickel into the system of fertilization of crops grown on leached Chernozem. The Nickel content in the leached Chernozem before development of crop rotation was generally close to Clark soils of the world (40 mg/kg) and significantly lower than UEC (80 mg/kg), which favors the production of high quality produce. After three rotations of the crop rotation without using fertilizers, the total content of Nickel and acid-insoluble form in the soil decreased slightly, but the number of the element extracted with both buffer and acid extractor, increased insignificantly. The decrease of the total content of Nickel and its reserve (acid-insoluble) fund in the soil we explain with the annual exclusion of the element with harvests crops from the fields, and the trend of increasing mobile and acid-soluble - mineralization of humus followed by acidification of the soil. Systematic mineral fertilization on field crop rotation was slightly up for the Nickel fund of the soil, but did not ensure the recovery of the initial level. At the same time, at fertilize crop rotation we observed a clear trend of increasing the number of rolling and acid-soluble Nickel. If we consider that the value of the MPC for moving Nickel is equal to 6 mg/kg, these changes may not have any negative environmental impacts, but rather will encourage the use of this ultra-microelement by plants