Qualidade do solo sob atividade agropecuária no sul do Amazonas

Abstract

The Amazon region has increasingly attracted the attention of researchers due to the vast wealth of diversity of this biome, composition and complex soil structures. However, the forest has been suffering major interference and changes in its natural structure through the advance and agricultural expansion in the Amazon region arising from anthropic practices, which has resulted in degradation, loss of soil quality and the sustainability of production environments. The objective of this work was to evaluate the physical quality of the soil under agricultural activity in the southern region of Amazonas, aiming to investigate the impacts arising from agricultural practices currently used by rural producers in the municipality of Humaitá-AM, using as indicators the physical attributes and the stock of carbon (EC) of soils. The study was carried out in the rural area of Humaitá-AM, in four different environments, being the cultivation of açaí, manioc, pasture and a forest area in three depths 0.00-0.05, 0.05-0.10 and 0.10-0.20 m, totaling 120 samples, collection was performed at 10 points in each studied area. The physical attributes evaluated were: textural analysis of sand, silt and clay fractions, soil density (Sd), weighted mean diameter (WPD), geometric mean diameter (WGD), soil penetration resistance (RSP), aggregate class < 1.00 mm, 1.00 – 2.00 mm and > 2.00 mm, total porosity (Tp), macroporosity (MaP), microporosity (MiP), gravimetric moisture (GM), soil organic carbon were also determined (COS), organic matter (OM) and soil carbon stock (EC). After the laboratory analysis of the attributes, tests of descriptive statistics were carried out and the means were compared by the Tukey test at 5% of probability, later, a multivariate analysis was carried out using the technique of analysis of principal components. According to the results obtained, it is concluded that the conversion of the forest area into agricultural use environments caused changes in soil attributes.