T. Tihanov
Department of Mechanical Engineering, Faculty of Techniques and Technologies, Trakia University, 8600 Yambol, Bulgaria

(Manuscript received 14 April 2026; accepted for publication 19 May 2026)

*e-mail: tihomir.tihanov@trakia-uni.bg

Abstract. This article examines the impact of various tillage machinery on the granulometric composition of soil. An analysis of literature sources dealing with the operation of moldboard ploughs, cultivators, disc harrows, digging machinery and rotary tillers under different soil conditions and operating modes has been carried out. It has been established that the type of machinery, depth of cultivation, soil moisture and working speed have a significant impact on the granulometric composition of soil. It has been established that moldboard ploughs provide good inverting of the soil layer and high level of coverage of plant residues, but often lead to the formation of larger aggregates and compaction of the subsoil layer. Cultivators, disc harrows and rotary tillers contribute to more intensive crushing and the formation of a finer soil structure, suitable for sowing crops. Digging machines are distinguished by better preservation of the soil structure, but with lower actual productivity. The analysis shows that the correct choice of a tillage machine and operating mode is essential for the granulometric composition of soil.