CORRELATION AND VARIABILITY OF SOIL PROPERTIES OF ARABLE СHERNOZEMS IN THE SOUTH OF THE CENTRAL RUSSIAN UPLAND

Abstract

Search for correlations between different soil properties and assessment of their variability is important for understanding soil functioning, allows more optimal planning of field and laboratory research and creates the basis for fertilizing management and precision agriculture. This work is based on the data on the content of organic carbon, pH, bulk density, texture (fractions 1-0,25 mm; 0,25-0,05 mm; 0,05-0,01 mm; 0,01-0,005 mm; 0,005-0,001 mm and <0,001 mm and <0,01 mm), exchange calcium and magnesium carbonates for twelve sites of plowed Chernozems studied in the southern part of the Central Russian Upland (Belgorod oblast). Soil samples were taken layer by layer every 20 cm to 3 m depth. Weak correlation was revealed among studied soil characteristics of the plowed Chernozems. The least correlation with other soil characteristics is characteristic of bulk density, organic carbon content, content of fraction 0,25-0,05 mm and 0,01-0,005 mm. Correlation between the content of bicarbonates and pH values is observed only for accumulative - carbonate horizon and transition horizons. The largest number of correlations between different soil characteristics is for the non-plowed part of humus horizon and the top of transition horizon. The least amount of correlations between soil characteristics was found at depths from 80 to 100 cm. Comparison of the coefficients of variations calculated for different soil layers of a single profile (i. e. intraprofile variability) and for the same soil layers but from different profiles (i. e. lateral variability) showed that the intraprofile variability exceeds the lateral one for the organic carbon, exchangeable potassium and calcium content.