Soil functions and in situ stress distribution in subtropical soils as affected by land use, vehicle type, tire inflation pressure and plant residue removal

摘要

Soil deformation due to compaction and shearing with heavy machinery is still one of the largest threats to soil functionality and thus to crop performance on arable soil. By determining the in-situ stress input and propagation due to tractor and harvester wheeling on two south Brazilian soils, a Typic Hapludox and a Typic Hapludalf, we aimed to investigate the consequences of different wheeling conditions on soil composition and functions. Stress state transducer (SST) sensors were installed in three to four soil depths to measure stress impact and propagation and to quantify the effect of different contact pressures by different agricultural machines, tire inflation pressures, and absence or presence of plant residues on soil under no-tillage (NT, each Hapludox and Hapludalf) and natural grassland (NG, only Hapludalf). Field measurements of principal stress al were amended by laboratory analyses to quantify changes of soil precompression stress sigma(p), air permeability, and water retention before and after the passage of a harvester.