DYNAMICS OF AGROCHEMICAL INDICATORS IN AGRICULTURAL SOILS OF THE KHOROSHIV DISTRICT OF THE ZHYTOMYR REGION

Abstract

The article examines the changes of the main agrochemical parameters in the soils of agricultural lands of the Polissia zone on the example of Khoroshiv district of the Zhytomyr region over the 20 years. The largest area of the analyzed territory is occupied by sod-podzolic soils (74.6% of the territory). These soils are characterized by low native fertility and require systematic application of mineral and organic fertilizers, liming. Based on the data of the VIII–XII rounds of agrochemical survey for the twenty-year period (2001–2021) conducted by the Zhytomyr branch of the state institution «Institute of soil protection of Ukraine», changes of  the main agrochemical indicators were analized: the content of easily hydrolyzed nitrogen, mobile phosphorus, exchangeable potassium and acidity. All analyzes of soil samples were carried out in accordance with current normative and methodical documents in the institution’s accredited laboratory. Consequently, the reduction of measures for restoration and preservation of soil fertility has led to a deterioration of the soil quality. The study established that the areas of land where deterioration of the agrochemical condition is observed have increased and parameters of agro chemical indicators of soil fertility in the last two decades tend to deteriorate. Оver the period from 2001 to 2021, on average, nitrogen content decreased by 13 mg/kg of soil (18.3%), mobile compounds of phosphorus decreased by 16 mg/kg of soil (20%), and mobile compounds of potassium by 15 mg/kg of soil (21.4%). The weighted average indicator of metabolic acidity decreased from 5.7 to 5.3 units (7%). As of the end of the analysed period. period soils with very low (95% of the total area) nitrogen content, medium (46%) and low (33%) mobile compounds of phosphorus, low (59.6%) and very low (31.2%) content of mobile compounds of potassium. Regarding the indicators of potassium content in soil samples 31.2% with a very low content, and low – 59.6% of the surveyed areas. The main part of the soils has a slightly acidic (36.2%) and moderately acidic (38%) reaction of soil solution.