Trophic level of arable soils of Ukraine and promising directions for optimizing nutrition of agricultural crops in modern conditions (expert analysis)

Abstract

The results of the expert assessment of the provision of the main arable soils of Ukraine on loess rocks with nitrogen, phosphorus and potassium and promising ways to optimize the nutrition of agricultural crops are summarized. The analysis uses samples from the database of agrochemical properties of soils of Ukraine, created on the basis of the stock materials of the department of agrochemistry of the NSC ISSAR and published data from the results of surveys conducted by the Institute of Soil Protection of Ukraine. Based on the identified patterns of the state and dynamics of phosphate and potassium systems of soils, statistical and mathematical analysis of data sets has theoretically substantiated the possibility of formalizing the assessment of the trophic state of arable soils under conditions of their extensive, intensive and post-intensive use. Mathematical models have been developed for extrapolation and interpolation of data on the content of mobile compounds in arable soils depending on natural or anthropogenic factors. It is suggested that traditional ideas about the fertility of arable soils on forest species, especially chernozems, are artificially inflated as a result of a number of objective and subjective factors. The main reasons for this phenomenon are named. According to the developed forecast, in 2025 the average weighted content of phosphorus compounds (P2O5) in arable soils of Ukraine will be 65-70, and potassium (K2O) - 70-72 mg / kg of soil. That is, the trophic level of arable soils will remain on the verge of low and average values of the provision of these elements for plant needs. It has been proven that the phosphate and potassium systems of soils as thermodynamic systems are characterized by high stability of values. It is possible to achieve a real increase in the trophic level of arable soils only by systematically adding compounds containing phosphorus and potassium in an active form from outside. An involuntary increase or, conversely, a decrease in the natural content of phosphorus or potassium in arable soils is impossible. The term "mobile" in relation to phosphorus or potassium in the soil is abstract, conditioned by analytical laboratory methods, and not by the needs of plants. The expediency of directing efforts to the development of new and improvement of existing agrotechnical and biotechnological methods for increasing the bioavailability of nutrients from both the soil reserve and fertilizers is substantiated.