Soil Compaction Due to Tractor Traffic

Horticulture in Mediterranean areas demand frequent tractor traffic for tillage and for the application of herbicides and pesticides, resulting in soil compaction. Soil compaction is one of the most important factors responsible for soil physical degradation. This compaction by agricultural machines can have adverse effects on crop production and the environment. Different methods have been proposed to estimate soil compaction intensity as a function of vehicle and soil properties such as the soil's water content, bulk density, and resistance to penetration. In this work the authors studied subsoil compaction based on wheel load in the terrain tillage and tillage in a region that was not previously cultivated. A small tractor (engine power 25 kW, type E-TCVS, and weight 1200 kg) was used in the tests. Results showed that the first passage of wheel traffic of the tractor, increases the soil resistance more than the second passage; for example, there is a big difference between the penetration resistance at initial state (2.22 daN/cm(2)) and after the first passage (5.72 daN/cm(2)), while the variation between the penetration resistance after first passage (5.72 daN/cm(2)) and after second passage (6.22daN/cm(2)) is relatively small. This shows that the first passage has the most significant impact on soil compaction.