Attributes of pedoindicator soils in areas cultivated with typical crops in the western Amazon, Brazil

Abstract

The crop systems adopted in the Amazônia region have been studied several times in terms of the variability and to indicate the soil attributes more sensitive to the different crops. Thus, the objective of this work was to apply multivariate techniques in order to identify the chemical attributes most sensitive to environmental changes in different crop systems in Western Amazonia, Brazil. The research was conducted in five rural properties located in the Humaitá city region, Western Amazonia, Brazil. There were selected four environments with natural characteristics (Native Forest-NF) and five cropping systems (Grazing, Cassava, Açaí, Agroforestry and Reforestation). In the selected areas, soil samples were collected at depths layers of 0.0-0.05 m; 0.05-0.1 m and 0.1-0.2 m and the following chemical analyzes were performed: pH in water, Ca2+, Mg2+, K+, Resin-P, phosphorus bio-available particulate (Pbp), OC, Al3+, H++Al3+ and from these results SB, T, t, m% and V% were calculated. Multivariate statistical techniques were used to verify similarities between the crop systems in the attempt to relate the crops grown and the chemical attributes. The multivariate analysis was essential in the crop systems distinction, as well as to describe the relationship with the chemical properties. The results demonstrate and reinforce the existing variability between crop systems, with emphasis on the variation in crop systems, compared to natural environments.