Impacts on land conversion of forest-use to agriculture in Southern Amazon

Abstract

In order to the information on the distribution and behavior of soils in southern Amazonas this study aims to investigate the impacts of vegetation changes on soil properties in southern Amazonas, using geostatistics and multivariate analysis in the context of soil-landscape relationship. The study will be conducted in areas submitted to the following conversions: a) Forest/cane sugar b) Forest/Grassland c) Forest/Agroforestry. In each will be installed a transect from the top, followed by the spike in the sense strand of trimming of the slope at a distance of 3,000 meters up the slope below the footslope or flooded. Along the transect, the soil will have its elevation measured for profile. In these points will be collected soil samples at two depths from 0.0-0.20 and 0.60-0,80 m, totaling three transects of 360 samples. In transects will be identified and demarcated areas by geomorphic criteria as recommended by Ruhe (1969) and Daniels et al. (1971). The limits of the slope units will be classified according to the model of Darlymple et aI., (1968). In places that are representative of geomorphic surfaces, and in the alignment of the transect, it will be established a network of 1 ha in each management unit, with its repetition in closest forest areas. These will be sampled at regular spacing of 10 to 10 meters (depths 0.0-0.20 and 0.60-0.80 m), totaling 121 samplings in each grid. Soil analysis will be physical, chemical, diffuse reflectance, magnetic susceptibility, x-ray fluorescence determination of the soil CO) evolution in the samples collected in the transect and in each hectare. The mineralogical analysis will be performed in some samples of the transect enough to do the calibration of the method of diffuse reflectance and in samples from subsurface diagnostic horizons of the trenches. The data will be analyzed by using multivariate analysis, statistics and geostatistics. (AU)