Prediction of the different genesis soils nitrogen systems status
Authors: Samokhvalova V. L. , Khristenko A. O. , Shedey L. O. , Samokhvalova P. A. , Karatsuba O. V. 
Published: March 2019

The method for predicting the levels of the easily hydrolysable nitrogen content in soils of various types of Polesie, Forest-steppe and Steppe climatic zones of Ukraine for the assessment of soil quality due to the background conditions, the influence of technological load (for the application of organo-mineral, organic and mineral fertilizer systems), and risk or influence of technogenic pollution by heavy metals (HM) is grounded. In the elaborated methodical approach is obtained a regression equation by the determination of new correlations of soil energy intensity indices (the calorific value of humus, soil energy reserves in a layer up to 20 cm) in conjunction with the humus state and the use of mathematical and statistical analysis for determining the value of easily hydrolysable nitrogen with the ability to predict the quality of soils of various genesis, with the further extension of the method algorithm for different soil types, climatic zones due to technogenic HM pollution and technological load. The technical result of the elaborated method: by improving the determination of the levels of the easily hydrolysable nitrogen content in soils of different genesis for the evaluation of their quality by identifying the most correlated, diagnostically applicable integral basic indicators of soil properties, which allow the informativeness to make managerial decisions and to predict the quality of soils of different genesis in the content of easily hydrolysable nitrogen, as a biogenic element, due to the background conditions and anthropogenic loads with increased accuracy, speed and informativeness. Elaborated method can find application in the ecological standardization of the content of biogenic macroelements, the normalization of loads (technogenic, technological) on the soil system, agroecology for solving the problems of organic agriculture, bioenergy and energy of soil formation; diagnostics, evaluation, forecasting of the soils nitrogen systems state; the quality of humus and macroelement status of soils on indicators of ecological and energy status; effective ecological management of soils due to the background conditions, as well as for various anthropogenic influences and in scientific research for the investigating of biogeochemistry and biogenic macroelements of soil cover. Separate provisions of the elaborated method became an integral part of the proposals on adaptation to the Nitrate Council Directive 91/676 / EEC of 12.12.1991 on the protection of water from pollution caused by nitrates from agricultural sources, as amended by Regulation (EC) № 1882/2003 Cross Nitrogen Balances Handbook. Prospective directions of research in the field of diagnostics, assessment, forecasting of the state of soils nitrogen systems and the normalization of the elemental composition quality, in particular, the content of nutrient nitrogen are determined. In order to overcome the biogenic pollution (excessive accumulation of nitrogen compounds) in the environment (plants, waters), the normalization of nitrogen content in soils of different genesis should include: a) determination of the maximum permissible levels of mobile mineral forms of nitrate nitrogen by the elaboration of environmental requirements for nitrates contamination with plant products; b) normalization of the content of labile easily hydrolysable nitrogen and / or a dose of nitrogen fertilizers in conditions of sufficient and excessive moistening, considering the rapid processes of transformation of nitrogen compounds in soils; c) normalization of the soil nitrogen mineral compounds content in conditions of insufficient moistening and slowing down the processes of circulation of nitrogen compounds of soils. Distinctive features and advantages of the proposed elaboration in comparison with known methods and approaches are: 1) the express obtain of the accurate projected levels of easily hydrolysable nitrogen as a nutrient in the soil with the improving the accuracy of soil diagnosis by the use of the basic integrated indicators; 2) providing opportunity for greater efficiency of forecasting data on the functioning of the nitrogen systems of different genesis soils, quality, environmental and energy state of soils due to the background conditions and anthropogenic loads while minimizing the cost of material resources; 3) empowerment of the user in determination of the easily hydrolysable nitrogen content in the soil without extensive chemical analysis by the choice of regression equations, based on the use of baseline soil properties of a particular type and subtype according to the available information; 4) versatility of the method by the suitability of detected dependencies of the proposed method for all soil types and subtypes, climatic zones and contaminants.