Changes to the physical properties of the soil after the passage of an agricultural tractor

*Corresponding author e-mail: vojtech.kumbar@mendelu.cz **This work was supported by the project ZETOR (EG15_ 019/0004799 – ZETOR TRACTORS a.s.) – Optimal aggregation of machines with a tractor (from 01.06.2017 to 31.08.2019). A b s t r a c t. The effect of the passage of agricultural machinery on the soil is influenced by, for example, the inflation pressure in tyres. This article describes the effect of different tyre inflation pressures (200 and 100 kPa) on selected physical soil properties in the field experiment. The undisturbed samples were collected both in and between the tracks at depths of 0 to 0.5 m and subsequently processed according to a valid methodology in the laboratory. The results indicate that fewer negative changes were found in the variant with a lower inflation pressure for all of the observed soil properties (front wheels load 2 990 kg and rear wheels 11 760 kg). However, the differences between the pressures were not statistically significant. The impact of different tyre pressures at greater depths has also not been proven to date. This may be attributed to the creation of a plough pan due to the long-term use of the minimization technique because the values of individual properties were balanced at a depth of 0.2 to 0.3 m. These depths do not react to further tractor compaction due to the accumulation of compaction. Changes to the values of soil physical properties caused by the passage of the tractor were statistically significant for both tyre pressure variants only at depths ranging from 0 to 0.1 m. K e y w o r d s: soil compaction, tyre inflation pressure, physical properties