Erodibilidade do solo em áreas sob ambientes naturais e antropizados no contexto socioambiental sul do Amazonas.

Abstract

The Amazonian soils have been undergoing severe changes caused by anthropic activities, among which the transformation of forest areas into cultivation areas stands out, which can cause significant changes in the attributes of the soils in different environments, resulting in the intensification of the occurrence of the erodibility of the soil. For this reason, the work aimed to determine the soil erodibility, its indicators, and to evaluate the applicability of the soil loss prediction equations proposed by Denardin (1990) and Flanagan & Livingston (1995) under natural and anthropized environments, in the socio-environmental context, in the southern region of Amazonas. Areas of approximately one hectare were selected in each study environment, of these, containing native forest 1 (FN1), native forest 2 (FN2), Cerrado, Cerradão and anthropized pasture environments, teak species (tectona grandis), Jenipapo (genipa americana) and mixed: subcultures (tectona grandis and genipa americana). In each environment, areas of approximately 1 hectare. The soil samples were collected at random using a Dutch auger, at a depth of 0.00-0.20 m, with 32 sample points per area, totaling 256 samples in 8 areas. Laboratory analyzes were carried out to determine the granulometric analysis, fractions of sand and soil organic matter (MOS). Erodibility was estimated using indirect prediction methods and the data were subjected to descriptive, multivariate statistical analyzes, compared by the Tukey test (at 5%) of Pearson's correlation probability and, finally, a factor analysis of the main components (CP1 and CP2). The results showed that activities involving burning, deforestation, logging, mining and agriculture practices in Amazonian soils must be planned in advance and conservation practices must also be applied carefully, since the beginning of land use, in order to preserve and increase the soil productivity and guarantee its use by present and future generations. There is a need to carry out environmental diagnostics to identify, characterize and map the areas with the highest occurrence of erosion in southern Amazonas, in order to ensure the conservation of biodiversity, environmental quality of land use and the guarantee of sustainable, environmental and socioeconomic development of the regional population. The evaluated areas show that FN1, FN2, cerradão and pasture have a high level of erodibility in relation to the cerrado, genipap, teak and mixed areas. High level of erodibility is considered the criterion of greater susceptibility to erosion, that is, soils that have great erodibility presented a higher predominance of the fraction of sands, factor K, Ki Kr and low clay content. The change in the use and occupation of the soil, by several anthropic activities and in an unplanned way, can alter and degrade the environment, impacting agricultural productivity, degrading the soil and causing economic instability on society, which accelerates even more the erosive process. However, with analysis of the evaluated areas, there is a need to monitor and adopt soil conservation practices, in order to minimize erodibility, contributing to the increase of sustainability and environmental quality.