Chemical soil properties in the river basin of Vacacaí-Mirim

Abstract

The levels of metals in soils have increased gradually with the modernization of agriculture which has occurred in recent years. The human action performed by man in nature is the main cause of this phenomenon. On this basis, the present study's aim is to evaluate changes in soil chemical properties due to different uses and occupations in the river basin of Vacacaí-Mirim. The technique used for analysis was EDXRF, where the values were spacialized with the aid of the software Surfer 10. Values for Barium ranged from the detection limit (DL) to 7,608.27 mg/kg-1 with an average of 1,286.71 ± 2,295.18 mg/kg-1, the concentration of Phosphorus ranged from DL to 2,327.02 mg/kg-1 with an average of 676.45 ± 700.05 mg/kg-1, Manganese ranged from DL to 5,533.51 mg/kg-1 with an average of 1,057.34 ± 1,380.81 mg/kg-1, the values for Silicon ranged 229,114.70 to 832,568.70 mg/kg-1 with a mean of 696,134.25 ± 144,950.56 mg/kg-1, Zinc concentration ranged from DL to 429.98 mg/kg-1 with an average of 145.725 ± 123.78 mg/kg-1. Based on these results, it is possible to identify that the concentrations of the metals studied and the land use are closely linked, since concentrations are higher in areas that have agricultural uses, which require larger amounts of chemicals. Thus, it can be observed that the soils under the uses of rice, soybeans and pasture had greater influence on the concentration of the element barium, phosphorus, however, had most influence by the land use in pasture and soybeans.