ASSESSMENT OF CONSTITUTIONAL BASE OF AGRO-GREY SOIL FERTILITY

Abstract

The general state of fertility should be assessed by at least two groups of parameters: dynamic (mobile nutrients, acidity) and constitutional direct - mineralogical, granulometric, organic and chemical composition, as well as constitutional indirect - cation exchange capacity (CEC), sorption capacity, buffering capacity. The purpose of the research is to study and evaluate some of the constitutional parameters of the fertility of the experimental agro-gray soil. The humus content in the soil (2%) corresponds to the minimum permissible level. The soil has a low value of the sum of exchangeable bases (7-8 mmol / 100 g of soil), which is 2 times less than the cultivated analogue. In the soil, the share of free HAs increased to 11.5-14.0% (abs.) And the content of HAs not associated with calcium decreased to 24.3-28.1%. In the mineral part of the thin soil fraction of agro-gray soil 1-5 microns in size in the 0-20 cm layer, the content of functionally inert minerals is 63% in total. The number of valuable mixed-layer formations increases with depth. To compensate for the loss of clay fractions, cover loam enriched in nitrate forms of nitrogen can be used. The experimental product contains about 2.7% of total nitrogen, mobile and total potassium is 1250 mg / kg and 0.20%, respectively, ECO - 48 mg-eq / 100 g.