Bioindicadores e diversidade de bactérias em ensaios com biochar e composto orgânico combinados com nitrogênio e inibidor de urease

Abstract

The soil microbial community is one of the most important functional components of soil biota being fundamental identify the factors that alter its composition and metabolic function. This study was conducted in microcosms with the addition of different compositions of organic and organomineral fertilizers formulated from biochar and organic filter cake sugar cane, nitrogen and urease inhibitor (NBPT). The incubation period of 28 days it was performed an assessment of the microbial respiration (RMS) and nitrogen volatilization (NH3). At 7, 14 and 28 days were estimated microbial biomass carbon (MBC) and the enzymatic activity. Genomic DNA soil, treatments, and the fragment was extracted from bacteria and archaeal 16S rDNA was amplified by PCR, the sequence being sequenced by pyrosequencing using the Life Technologies Ion platform torrenteTM. The quality sequences obtained were analyzed using the Qiime program (Quantitative Insights Into Microbial Ecology) and the assigned sequences using GreenGenes taxonomy database. The larger RMS values and CBM were observed in treatments with the addition of nitrogen. These treatments shown increased activity of enzymes FDA and urease, and an opposite answer was found for the activity of betaglucosidase enzymes, phosphatase and dehydrogenase whose greatest response was observed in treatments without nitrogen. In control treatments, biochar and organic the predominant phyla were Proteobacteria, Bacteriodetes, Acidobacterias, actinomycetes and Verrucomicrobia. The addition of nitrogen significantly reduced the abundance of these phyla and increased the abundance of Firmicutes phylum that prevailed in all treatments with nitrogen. It was observed reducing NH3 volatilisation of the organic compound and treatment with biochar. The lower volatilization occurred in treatment with biochar indicating its potential as fertilizer to reduce losses of nitrogen. Based on it, this study can contribute to the advancement of fertilization techniques that improve soil fertility and sustainable use of agro-ecosystems.