Microstructural Evaluation of an Ultisol and its relation to the history of tension and soil management

Abstract

The lack of information of the microstructure of the soil and its association with physical and mechanical, not always possible to assess the actual effect of stress history, land use. However, the use of micromorphology techniques combined with image processing can provide areas of physics and soil conservation in the characterization and troubleshooting, enabling better interpretation of attributes that affect the compactness of the soil, as well as its relations with the external factors such as stress distribution in the ground and use. The objective of this research was to evaluate the microstructural behavior of an Ultisol under different loads (contact pressures), water contents and usage through techniques micromorphology. Assays micromorphological, physical and mechanical properties were performed on soil samples collected in the 0-0.10 m layer, under the use of Native Forest (MT) and Cultivation of Banana (CB) in permanent preservation areas (Law No. 4771/1965), along the Ribeira river (Sao Paulo, Brazil). Undisturbed samples were subjected to two states of consistency: a) Plastic b) tenacious. Then were subjected to uniaxial compression tests, and the following loads applied to the sample: preconsolidation pressure sp; 25 kPa and 1600 kPa. There have higher porosity compared to rounded pores elongated in all conditions analyzed. The load of 1600 kPa showed higher amounts of pores rounded compared to the other loads (25 kPa and sigma p) has the pores to elongate lighter loads showed greater amounts of the same due to the greater compression of the samples. Tenacious consistency, the effects of the factors studied varied in the observed results. The digital image processing allowed us to assess the effects of the factors studied in an Ultisol, being a sensitive tool in the evaluation of soil porosity. The intensity of the applied load, moisture and land use. The factors applied load intensity, humidity and land use, causing changes in the shape and distribution of the porosity of the soil.