FEATURES OF THE AGRICULTURAL USE OF SOD-CARBONATE SOILS (RENDSIN) OF THE VOLYN FOREST

Abstract

The features of sod-carbonate soils (rendzin) and their contiguity to Upper Cretaceous deposits within the boundaries of the Volyn Polissia are considered. The research was conducted in two areas and similar results were obtained. The term "rendziny" is briefly explained and their genesis, soil profile morphology, humus reserves, processes of humus formation and dehumification are defined. The most lasting effect of humus accumulation is noted when organic fertilizers are applied. This indicates that the use of organic and organo-mineral fertilizer systems leads to the stabilization of humus accumulation in the arable layer of the humus horizon.To maintain a high level of humus formation, it is necessary to apply organic fertilizers, and for a high degree of enrichment of humus with nitrogen, it is necessary to supplement them with mineral fertilizers. Of all the applied fertilization systems, the most optimal is the organo-mineral (combined) system (N60P60K120+8.9 t/ha of manure), which contributes to the formation of a powerful humus horizon characterized by the highest thermodynamic stability of the humus complex.The transformation of colloidal forms of humus was noted. When plowing rendzin on control (without fertilizers), the content of GH in the plowed layer decreases by 2 times, which indicates increased mineralization due to plowing. The use of fertilizer systems makes it possible to restrain PG mineralization by 16–40%, and the organo-mineral system exerts a great influence on its stabilization.