Study of the influence of complex humatised mineral fertilizers on gray soils fertility

The aim of the research is to study the effectiveness of complex humatised mineral fertilizers (CHMF) on fertile quali- ties of gray soil. The problems were to study the influence of CHMF on fertile qualities of gray soil, basing on field experi- ments, as well as to study the optimal ratio of constituent parts of CHMF. The objects of the research were CHMF in their structure containing GMUK (including ammonium nitrate, sodium humate and trace elements, as well as glauconite- potassium component) and phosphoric component (phosphorites), as well as gray soils. The research methods included field experiments, soil sampling, determination of qualitative characteristics of the soil (humus, labile phospho- rus and exchange potassium). Investigated soils were medi- um loamy gray soils of old irrigation. It was established that the using CHMF would lead to the increase humus content in the soil, labile phosphorus and exchange potassium. After using CHMF, relatively to their initial values in the soil (before using CHMF), the soil content was: humus - from 178...