Sistemas integrados de produção sob as características microbiológicas de um argissolo

Abstract

The crop-livestock-forest integration system (iLPF) is an alternative for the conservation of natural resources. Its main essence is to include annual crops and silvicultural species together with pastures situated in the same area, in order to increase profits, maintain and improve the chemical, physical and biological attributes of the soil. In this sense, the objective was to evaluate the behavior of microbiological attributes of a soil at different depths and cropping systems in the Amazonian ecosystem. The study was carried out from November 2015 to August 2016, in private property called Fazenda São Paulo, located in the vicinity of Vila do Roxinho, in the municipality of Iracema, state of Roraima, Brazil. A completely randomized design was used in a 4x2 factorial scheme with four replications. Four areas (crop-livestock integration (iLP), crop-livestock-forest integration (iLPF), native forest and an extensive pasture area) and two soil depths (0-10 and 10-20 cm) were evaluated. The microbiological and chemical attributes of the soil were evaluated. The data were submitted to analysis of variance and, according to the significance, the means comparison test was performed. It was verified that pasture and native forest stood out over the other systems (iLP and iLPF), in the rainy season with mean values of BMS-C of 149,56 and 134,51 mg C kg soil-1. Soil Basal Breath was higher (0,92 mg C - CO2 ∙ kg -1 soil ∙ h-1) in the area with iLPF in relation to the other systems in the rainy season. The native forest presented the highest microbiological quotient of the soil in the Dry and Rainy Periods (5,40 and 5,14%). Nitrogen from Biomass Plus in the dry period was higher in the Pasture and Native Forest areas in relation to the other systems, with values of 615,59 and 614,48 mg N kg soil-1 respectively. The areas of iLP and iLPF presented values of Total Carbon of 6,87 and 7,40 g C kg-1 soil respectively, being the depth of 0-10 cm of the highest average content. It was concluded that the Pasture and Native Forest systems presented the best microbiological attributes of the soil, independent of the periods studied. The 0-10 cm layer in the rainy season presented the best results for soil microbiological attributes. Basal Breath of Soil in the rainy season was the microbiological attribute that obtained a more significant correlation, whereas in the Dry Period the attributes that most correlated were the Carbon Plus of the Soil Microbial Biomass and the Soil Microbial quotient.