Просторово-часова нерівномірність забезпечення ґрунтів рухомими мікроелементами

Abstract

Goal. To determine the spatial and temporal variation of the content of mobile trace elements in the arable layer of zonal soils of the Left Bank Forest Steppe of Ukraine. Methods. Field, soil monitoring, laboratory-analytical — for determination of mobile forms of trace elements in the soil by the method of atomic absorption spectrometry with extraction with ammonium acetate buffer solution with pH 4.8, and statistical. The research was conducted during 2018–2020 at 2 soil-agrochemical land ranges. The soil cover of one of them consisted of chornozems and dark gray podzolized soils, and of the other, typical chornozems and their varieties. Each of the ranges was divided into 24 plots, where twice a year (April–May, and September–October) pH of saline, organic carbon, moisture, and mobile Zn, Cu, and Mn in the arable soil layer were determined. Results. During the research period, the average saline pH parameters at the first land range varied from 4.4 to 5.0, and at the second land range from 5.8 to 6.1. At the first land range, the average content of Zn increased from spring to autumn from 0.63 to 0.81 mg/kg, Cu — from 0.25 to 0.38, and Mn — from 20.0 to 27.5 mg/kg. Conversely, on chornozems of typical content, Zn decreased from spring to autumn from 0.79 to 0.52 mg/kg, Cu from 0.35 to 0.16 mg/kg, and Mn did not change significantly. A very high level of variation was observed within each range, especially for Zn and Cu. However, centers of concentration or impoverishment of the soil on mobile trace elements mostly did not have a stable location. The spatial distribution of pH had a significant negative correlation with Mn, and in certain periods of observation, also with Zn. Conclusions. Mobile Zn, Cu, and Mn had significant temporal dynamics in the arable layer of the zonal soils of the Left Bank Forest Steppe, which was manifested in an increase in their content from spring to autumn under an acidic reaction of the environment and a decrease in Zn and Cu under close to neutral pH values. The variability of trace elements within each range was high, with coefficients of variation of 25–71% for Zn, 28–76 for Cu, and 9–52% for Mn. The closest negative relationship between Mn content and soil pH (correlation coefficients – 0.4––0.85) was noted in the samples of the experimental land range «Novyi Korotych» during the research periods.