Soil cover structure and transformation of morphometric parameters of Haplic Chernozems under no-tillage

Abstract

The results of the field experiment have been analyzed, it was set up on two experimental fields (with an area of 2.4 hectares each), where two different agricultural techniques – traditional and no-till – were applied. Diagnostics of morphometric parameters of typical chernozems such as: the thickness of the A1 horizon, A1 + AB horizons and the depth of carbonates reaction with 10% HCl, has shown that some changes in soils and soil cover had occurred in the fields over 8 years. The integral indicator of soil productivity is the thickness of the humus horizon, it demonstrated trends to decrease and increase in the soil cover structure of the experimental fields with different compositions of chernozem subtypes. The trends result from both climate change and periodic dry periods, which are not typical of the region, and from the change of traditional technology to no-till. The carbonates leaching from chernozem profiles in all variants of the experiment decreased, which correlates well with climatic indicators, changing with the seasons of the year. Chernozems with thin humus layaer and reacting with HCl close to the surface do not require liming. The revealed changes are not statistically significant, they reflect the resistance of chernozems to the variability of natural and anthropogenic factors of soil formation. Crop residues on the soil surface under no-tillage reduce physical evaporation, which contributes to moisture accumulation in the soil. The use of cover crops in winter also increases the moisture reserves, which are consumed by the plants during the summer growing season. Information on the transformation of morphometric parameters allows making temporal and spatial corrections in the applied agricultural practices (crop rotation, fertilization, the use of cover crops, herbicides and pesticides).