Effects of tractor forward velocity on soil compaction under different soil water contents in Tunisia

Africa is the second continent suffering from soil compaction; studies of this phenomenon must be multiplied in order to overcome problem. Very few have been conducted Tunisia understand compaction, its causes and effect on properties. The research was experimental field at Higher Institute Agronomy Chott Mariam, Sousse, Tunisia. main objective study evaluate different speed tractor compaction soil, that is, no (C0), 1 (C2) = 4 km h-1, 2 (C3) 9 h-1 hydraulic physical properties a silt loam texture under three natural moisture conditions: H0, H1 (15 days later), H2 (30 later). Each test run limited one pass. Undisturbed cores were collected topsoil (0-10 cm), 10-20 cm subsoil (20-30 cm) below trace wheel site. Soil level determined by penetration resistance using penetrologger. Bulk density then impact two frequency passages conditions compaction. For initial bulk 1.38 Mg m-3. After pass, highest degree observed with (C1) which signi?cantly changed resulting values up 1.74 m-3 compacted H1, significantly above critical value 1.6 for soils clay content 17.5%. high affected topsoil. results demonstrate degrees levels could greatly influence ways. Even relatively low water contents, capacity, substantial top induced after Key words: speed, moisture, resistance, density.