Aspects of physical and chemical soil attributes in natural environments and areas with agroforestry system in southern Amazonas

Abstract

The Amazon region, in general, has native forest and natural grasslands, with high acidity and high aluminum saturation, which is characteristic of Amazonian soils. The natural state of the vegetation and the soil in a preserved state, tend to favor development or not depending on the soil conditions. Soil quality is based on biological, physical and chemical aspects. The objective of this work was to evaluate the physical and chemical attributes of the soil in areas of Agroforestry System, Cerrado, Cerradão and Native Forest in the region of Humaitá, Amazonas. Thus, for each study area, soil samples were randomly collected, totaling 144 samples, being the sum of the two periods of the year. Physical and chemical analyzes are carried out. For statistical analysis, univariate analysis of variance (ANOVA) and multivariate analysis of variance (MANOVA) were used. The silt fraction was predominantly high, the forest presented a greater amount of porous spaces, with satisfactory total porosity and macroporosity, the average values of the gravimetric and weighted aggregation indices were higher in the forest, cerrado and cerradão. Acidic pH, Al³⁺ high in forest, Ca highlighted in teak, genipap and mixed. Through the principal component analysis, it was possible to observe an overlap of the cerrado, forest and cerradão environments, showing a greater similarity between the attributes of these environments.