Excessive soil compaction is an increasing problem in modern agriculture. Investigations carried out abroad and in many countries point to different causes and effects of such soil compaction. This paper presents part of results of the much wider investigations of phenomena occurring between tractor tracks and soil. The experiment includes one type of agricultural soil and two types of tractors: Caterpillar CHALLENGER-65, Illinois, USA and TG 160P, “14 October”, Krusevac, Yugoslavia. The results lead to important modification characteristics: soil penetration resistance, total porosity, soil bulk density and soil treading monitored as very important soil parameters. The investigations are to be continued.
