Caracterização química do solo, quantificação de carbono e nitrogênio da biomassa microbiana e avaliação do papel dos microorganismos na transformação dos resíduos orgânicos, Tailândia, Pará

Abstract

The soil chemical attributes, microbial population, carbon and nitrogen of the microbial biomass were analyzed in order to evaluate the changes caused by the management in the replication experiment of Terra Preta Nova (TPN)soil located in the municipality of Tailândia (PA).The treatments consisted of organic waste found in large scale, such as: coal (C), saw dust waste (RP5), shredded blade waste (RLT),bone waste (RA) and blood and fat (5). The quantification of fungi and bacteria were determined using the "Pour Plate" counting technique on Petri dishes. The carbon (CBM) and nitrogen (NBM) contents of soil microbial biomass were determined by the fumigation-extraction method. The highest pH value was detected in the charcoal-only treatment (C). The P reached maximum values of 344.00 mg dm? in the treatment that contained the greatest variety of added residues (C+RP5+RLT+RA+5), presenting well evident variations in plots that contained bone waste (RA). Ca showed higher values in the C+RP5 treatment and Mg in the treatment where there were all mixtures (C+RP5+RLT+RA+5) and RLT+RA. For most of the treatments the K contents were considered low. There is a close relationship between the behavior and availability of nutrients in the treatments analyzed and a clear increase in their concentrations in the plots where residues were incorporated, compared to the original soil plots. Regarding microbial diversity, the results showed that the effects of the application of the residues studied were more significant in the population of bacteria, and under application C+RLT+RA, the differences in relation to the population of fungi were more pronounced. The different types of residues and the various combinations that were used favored differently the increase in the carbon and nitrogen content of the soil microbial biomass. The additions of residues to the soil demonstrated that the soil can recover soil carbon contents in the medium term.