Abstract Agriculture needs methodologies that assist in the determination of soil attributes and variability mapping attributes with greater levels of detail. Therefore, the objective of this research was to evaluate magnetic susceptibility as auxiliary variable for estimating soil attributes in areas of Indian Black Earths in the south of Amazonas State. Three Indian Black Earth areas are located in the municipalities of Apuí and Manicoré - Amazonas, under uses with coffee, cocoa and pasture. The soils were collected at the crossing points in the depth of 0.00 - 0.20 m, making a total of 88 sampling points/area, and totaling 264 samples. The points were georeferenced for geostatistical modeling. After that, physical and chemical analyzes were performed to obtain the values of soil and magnetic susceptibility attributes. Descriptive statistics, Pearson correlation, linear regression and geostatistical analyzes were applied for Pedotransfer Function modeling and the spatial variability of the analyzed attributes. Magnetic susceptibility showed a high degree of spatial dependence in the study areas, high range values, correlating with most of the assessed attributes, mainly physical, indicating potential in the prediction of the attributes in these environments. Pedotransfer functions vary among IBE’s sites in attribute prediction, ensuring moderate estimates for predicting soil attributes in IBE’s areas.

Abstract This article presents the identification of soil use potential for different agropastoral and forest scenarios, using an indicator for erosion susceptibility from the spatialized Universal Soil Loss Equation (USLE). All USLE factors were spatialized using ArcGis 10.5 software, for the case study of the Cachoeira Cinco Veados Watershed-RS. To determine the R factor, we used the Cassol et al. 2007 equation and a 33-year series of rain data from six climatic stations. For the K factor, published values for the soil classes: Entisol, Ultisol, Oxisol, Molisols were used. From the DEM, the LS factor was obtained, considering six slope classes (0-3, 3-8, 8-20, 20-45, 45-75, >75%). In addition to the actual land use situation in the watershed, nine scenarios were proposed for the C factor. The value of 0.5 was used for the evaluation of conservation practices (P factor). Considering scenarios of current use situation along with the nine other scenarios, the results showed that, by identifying the most susceptible areas in each scenario, it is possible to construct an indicator map of soil compatibilities for each use, considering sustainable limits of soil losses. Therefore, this resulting map has potential use as instrument for land use planning and zoning studies.