Multivariate analysis in the evaluation of soil attributes in areas under different uses in the region of Humaitá, AM

Abstract

The recognition of the influence of management practices on soil physical and chemical conditions is substantial for sustainable agriculture. For this reason, this study was developed for the purpose of evaluating the behavior of soil attributes under different uses in the region of Humaitá, AM, using multivariate statistical methods. The study was developed in 8 rural properties producing bananas, grassland, maize, coffee, cassava, vegetables, agroforestry system and a forest fragment. Samples of soils with preserved structure in the 0.0 - 0.10 and 0.10 - 0.20 m layers were randomly collected in 5 small trenches per area, totaling 32 samples in the management systems, to determine the physical and chemical attributes. The data were then submitted to univariate and multivariate statistical analysis. Exploratory data analysis (principal components and dendrogram) and frequency of environmental covariates was efficient in distinguishing production environments, so multivariate classification based on physical and chemical attributes of the soil can help in the proper planning of land use. The analysis of the principal components indicates that the BD presents direct dependence with the SPR, signaling the use of the soil with grassland the only one in the process of compaction. Soil acidity is the main limiting factor for crop development, requiring the adoption of pH corrective practices with improvements in nutrient supply. The conversion of the forest to grassland maintained the structural characteristics of the soil, while the other uses increased improvements in physical quality and soil fertility.

Soil chemical attributes in areas under conversion from forest to pasture in southern Brazilian Amazon

“…We attribute this to the use of fire to clean the areas, which due to the increase in nutrients present in the ash into the soil provided a higher pH and the availability of nutrients 2 . However, when converting to pastures, due to Amazonian soils being naturally acidic, it is necessary to adopt corrective practices and improve the supply of nutrients 32 . www.nature.com/scientificreports/…”

Avaliação da fertilidade de áreas de terra preta de índio no sul do Amazonas

“…A expansão da fronteira agrícola tem avançado sobre a região norte do Brasil, diversas áreas de floresta têm sido desmatadas e incorporadas ao sistema produtivo. No entanto, essas áreas apresentam solos de baixa fertilidade natural, em geral ácidos e pobres em cátions básicos, caracterizado principalmente pela baixa disponibilidade de fósforo e reserva insuficiente de potássio (Pantoja et al, 2019). Por outro lado, o atual modelo de agricultura convencional, eventualmente, utiliza práticas agrícolas incompatíveis com as particularidades dos biomas brasileiros, sobretudo, num ecossistema frágil como o amazônico (Kohler et al, 2021).…”