Soil Structure and the Effect of Tillage Systems

To indentify the best soil management practices, it is necessary to quantify the modifications to the soil structure. Three different management practices were compared for short time: superficial tillage, medium tillage and conventional deep tillage. Tests were carried out over a sandy loam soil in the Higher Institute of Agronomy of Chott Meriem (Tunisia). Tillage was followed by a first resumption 10 days after tillage and a second one 20 days after. The studied parameters were measured at initial state and after each operation. Soil structure was characterized by its resistance to penetration using an electronic penetrometer and its bulk density. In soil tilled by conventional system with mouldboard ploughing, soil resistance decreased for a depth of 50 cm. In contrast, medium tillage with discs plow showed higher values of soil resistance in both the surface layer (10 cm) and the plowing depth (20 cm). Superficial tillage using discs harrow (Offset), showed higher values of soil resistance than the other tillage techniques. This study will be followed up to assess the evolution of these parameters over time.