Agrophysical condition of chernozem as a criterion for its readiness for soil tillage minimization
¹Dmytro Motornyi Tavria State Agrotechnological University, 66 Zhukovsky Str.,
UA 69600 Zaporizhzhia, Ukraine
²National University of Life and Environmental Sciences of Ukraine, 15, Heroyiv Oborony Str., UA03041 Kyiv, Ukraine
³Cherkasy State Agricultural Experimental Station National Scientific Centre, Institute of Agriculture of NAAS of Ukraine, 13 Dokuchaieva Str., Kholodnianske village, Cherkassy district, UA20731 Cherkassy region, Ukraine
⁴Latvia University of Life Sciences and Technologies, Institute of Engineering and Energetics, Faculty of Engineering and Information Technologies, Ulbroka Research Centre, 1 Instituta Str., Ulbroka, Ropazu Region, Stopinu Municipality, LV 2130 Latvia
⁵Estonian University of Life Sciences, Institute of Forestry and Engineering, 56 Kreutzwaldi Str., EE51006 Tartu, Estonia
*Correspondence: jyri.olt@emu.ee
Abstract:
The objective of this study was to develop an agrophysical criterion for assessing the condition of leached chernozem under systematic shallow tillage for six years, using differential porosity, crop productivity, and energy efficiency as indicators. The results were compared to those obtained under conventional ploughing, with the goal of evaluating the feasibility of further tillage minimization in a short-rotation grain crop rotation system. The study employed standard research methods, including field observations, laboratory analysis, mathematical statistics, and comparative-calculative approaches. Under shallow tillage, the median bulk density in the 0–30 cm soil layer was higher by 0.03 g cm–3 compared to ploughing, while the standardized density range remained similar across tillage systems. However, both the upper and lower typical values increased by 0.02 g cm–3 under shallow tillage. The coefficient of variation for bulk density was 1.85 times higher under ploughing than under shallow tillage. Differential porosity measurements across five crops in the sixth year of the trial revealed that in spring, shallow tillage resulted in higher bulk density (by 0.06 g cm–3), lower total porosity (by 3%), and a 6.0% reduction in air-filled pore volume compared to ploughing. At the same time, the ratio of water-filled to air-filled pores approached an optimal 1:1 balance under shallow tillage, whereas ploughed soils showed a dominance of air-filled pores. Systematic use of both ploughing and conservation-oriented shallow tillage over five years in a five-field grain-row crop rotation produced similar levels of productivity in terms of yield, energy efficiency, and output of grain and feed units. While productivity indicators under ploughing remained stable relative to the mean, shallow tillage demonstrated a positive trend. This trend is associated with the completion of the transition period following the cessation of deep ploughing and the shift toward preliminary deep chisel tillage, followed by systematic shallow tillage at a depth of 10–12 cm.
Key words:
bulk density, leached chernozem, ploughing, shallow tillage, soil moisture