Soil Chemical and Physical Attributes in Recovering Areas in the Southern Amazon

Abstract

The recovery of soil quality and forest regeneration is of fundamental environmental importance, especially in the Amazon biome. The objective was to evaluate the contribution of soil’s physical and chemical attributes in degraded areas in recovery process with different ages and compared to adjacent degraded areas cultivated with grassland, in the Southern Amazon. For this, was used areas located in the south of the Brazilian Amazon and four different areas were chosen, with 6 years of recovery (APP-6), 3 years (APP-3), degraded (APPD) area and degraded areas cultivated with grassland (DP). With emphasis on the physical variable bulk density soil showed averages of 1.37± 0.052 g cm-3 (APP-6), 1.49± 0.066 g cm-3 (APP-3), 1.55± 0.055 g cm-3 (APPD) and 1.67±0.077 g cm-3 (DP), respectively, and there was a decrease in soil density with longer area recovery time. As for the soil chemical variable of P observed averages of 18.46±2.74 mg kg-1(APP-6), 2.86±1.73 mg kg-1 (APP-3), 1.46±0.69 mg kg-1 (APPD) and 1.1±0.20 mg kg-1 (DP), there was a high increase in P in areas with longer recovery time. Study of comparison of means, was possible to elucidate the relationships between the soli’s chemical and physical attributes in the four areas studied. The results showed a greater supply of organic carbon, phosphorus, exchangeable cations (K+, Ca+ 2 and Mg+2) to APP-6 in relation DP. APPD e APP-3 areas. Similarly, the improvement in the physical attributes of total porosity and the bulk density of the soil in the area of APP-6 years of recovery, in comparison with the other areas (DP, APP-3 e APPD).