Indicadores microbiológicos de qualidade do solo associados com a produtividade e com sistemas de manejo do cafeeiro em áreas dos domínios Mata Atlântica e Cerrado de Minas Gerais

Abstract

Coffee production has great economic and social importance in Brazil and Minas Gerais. The coffee sector faces significant challenges to increase efficiency, with soil quality being an essential factor to sustain production. In this context, microbiological indicators are valuable tools for monitoring and predicting changes in soil quality, due to their sensitivity and diagnostic potential in management systems, as demonstrated by Aragão et al. (2020) in coffee crops, under a homogeneous condition in the municipality of Patrocínio, Minas Gerais. Therefore, this study aims to evaluate the association between soil microbiological indicators and coffee crop productivity in the Atlantic Forest domain, but now under heterogeneous conditions, and also to compare the impact of different coffee production systems on soil quality in the Cerrado. For this purpose, soil samples were collected in the municipality of Santo Antônio do Amparo, Minas Gerais, on two properties: Fazenda da Lagoas and Fazenda Samambaia. The samples were obtained in the dry season of 2021 and the wet season of 2022, from five pairs of plots under similar production conditions, each pair consisting of a plot with higher and a lower productivity, highlighting the heterogeneity conditions between the five selected pairs. In the Cerrado, samples were collected from seven farms in the municipality of Patrocínio, including six plots under a conventional system, six under a regenerative coffee system, and six native forest areas. The experimental procedure consisted of collecting five composite samples from each plot. The following microbiological attributes were evaluated: Microbial biomass carbon (MBC), microbial basal respiration (MBR), metabolic quotient (qCO2), activities of the enzymes urease (Ur), β-glucosidase (β-gly), arylsulfatase (Aryl), acid phosphatase (Phosph), and fluorescein diacetate hydrolysis (FDA). The chemical and physical attributes were: texture, pH, organic matter (SOM) and nutrients. In the Atlantic Forest domain, the microbial indicators, CBM, Ur, β-gly and Aril allowed to discriminate, mainly in the dry season, plots with different levels of productivity and were positively associated with the highest coffee productivity. In the wet season, only CBM and Ur were associated with the areas of highest productivity. On the other hand, qCO2 was associated with the areas of lowest productivity. In the Cerrado, the native forest areas presented greater activity of the soil microbiological indicators CBM, RBM, Aril, ADF, Fosf and Ur, which were positively correlated with these areas compared to the coffee areas in both seasons. In the regenerative coffee management system, higher values of CBM indicators and enzymatic activities, such as Aril and ADF, were observed during the dry season. In the wet season, the CBM, RBM, Aril, β-gly, FDA, Phosph and Ur indicators showed higher values, followed by the results of the conventional coffee management system.