Edafología. Volumen 7-2. Mayo 2000. pag 75-90.
The soil redistribution due to the conventional tillage practices represents a very severe process of soil erosion and degradation and of strong transformation of the soil-landscapes in Mediterranean agricultural lands. Several soil translocation models based on field experimental data are presented, in which the soil displacement due to mouldboard ploughing is calculated as a function of the relieve and tillage operation characteristics. The results indicate that soil movement rates (kg/m) are proportional to slope gradient; while the net rates of soil movement are related with the morphology and curvature of the hillslope: soil loss occur on convexities and deposition take place in concavities. Among effects of soil redistribution by tillage which produce a strong modification of soil profiles and soil-landscapes can be highlighted: i) soil truncation by loss of upper horizons; ii) replacement of superficial horizons within the cultivation layer, and iii) formation of false truncated soils.
Key words: Tillage erosion, Soil redistribution, Soil degradation, Truncated soils, Mouldboard plough.