Fractional Composition of Mineral Phosphates of PodzolicChernozem after Long-Term Application of Fertilizers in Field Crop Rotation

Abstract

Phosphorus content in the soil, features of the profile distribution, the proportion of organic and mineral compounds and other indicators characterize the level of soil fertility. Therefore, studies of the phosphate status of different soil subtypes in different agrocenoses are relevant. The aim of the research was to study the change in the fractional composition of mineral phosphates of podzolicchernozem compared to fallow land after the application of different fertilizer systems in the field crop rotation of the Right Bank Forest-Steppe. The content of mineral phosphates in the Chang and Jackson method in the Ginzburg-Lebedeva modification was determined in the soil from a layer of 0-20 cm with photocolorimetric determination of phosphorus by the Denigz method modified by Truog-Mayer. Studies have shown that podzolic heavy loam chernozem in the forest has significant reserves of potentially available phosphorus for plant nutrition. After 55 years in the field crop rotation, depending on the characteristics of the fertilizer, its content changed from 0.09% to 0.27% P2O5 (with the content under the fallow 0.10%). Under the influence of natural and anthropogenic factors in the soil is the transformation and regrouping of compounds and fractions of phosphorus. In this case, sparingly soluble phosphates can be converted into active forms and become potentially available for plant nutrition. Fertilizers are significantly poured on the fractional composition and gross phosphorus content. The content of gross phosphorus in the composition of mineral y of 0-20 cm is from 67-69% under mineral to 61-62% of gross phosphorus under organic fertilizer system. The main share of mineral phosphates in podzolic heavy loamed chernozem is represented by Ca-P calcium phosphates, which is determined by the genetic characteristics of this soil subtype. According to the content of mineral phosphate fraction in the soil layer of 0-20 cm, it can be presented in the following series: Са-РІІ>Са-РІІІ>Са-РІ>Fe-P>Al-P. The phosphate level of podzolicchernozem can be increased by applying fertilizers