Mineralização de resíduos orgânicos no solo em condição de campo

• Autor(a) principal: Paula, José Roberto de
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/724
• topic: Recursos hídricos; Resíduos orgânicos; Water resources; Organic Waste; CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA

The decomposition and mineralization of organic carbon and nitrogen from manure of cattle, laying hens and pigs, and urban waste compost and sewage sludge, were monitored in field conditions, when these residues were incorporated or applied superficially in Red-Yellow Latosol (LVAd) in the city of St. John the Evangelist - MG. For this, the residues were incubated for 360 days, during which samples were taken for analysis of oxidizable organic carbon (COfo) and total nitrogen (NT), organic (NO), ammonium and nitrate. When incorporated into the soil mineralization rates of COfo estimated, using the first-order exponential equation set (TmCOfoEst) ranged from 24,0 to 120,5%. The constants of decomposition of COfo (kc) of varied residues incorporated 0,000354 d-1 (0,129 year-1) to 0,000708 d-1 (0,258 year-1). The constants of decomposition of COfo (kc) applied superficially to the waste receiver soil ranged from 0,000866 d-1 (0,316 year-1) to 0,002696 d-1 (0,984 year-1), however, to form surface application of the waste and under the conditions of this work, the calculation method TmCOfoEst was not suitable in view unrealistic values that were obtained. Mineralization rates calculated using the parameters of the exponential equations of first order (TmCOfo(L)), showed a variation from 20,3 to 60,1% and were more consistent considering the condition of the surface application of waste. Receptor incorporated in the soil, the rate of mineralization COfo waste, calculated by taking the initial oxidizable organic carbon (CO(i)) as reference (TmCOfo(i)), varied from 34,0 to 92,7% and when wastes were applied at the soil surface, the TmCOfo(i) ranged from 55,1 to 100,0%. When added to soil mineralization rates of NO estimated, using the exponential equations of first order set (TmNOEst) ranged from 13,2 to 60,2%. The constant average accumulation of nitrogen (kN) of the residues incorporated ranged from 0,000179 d-1 (0,065 year-1) 0,000975 d-1 (0,356 year-1). When applied superficially to the ground TmNOEst ranged from 18,6 to 64,6%. The constant average accumulation of nitrogen (kN) of waste disposed on the surface ranged from 0,000085 d-1 (0,031 year-1) to 0,002688 d-1 (0,981 year-1). When incorporated into the soil, mineralization rates of NO waste, calculated by taking the initial organic nitrogen (NO(i)) as a reference, TmNO(i) ranged from 40,7 to 72,5%, and when residues were applied on the surface of the soil, TmNO(i) ranged from 51,3 to 70,4%. Regardless of the forms of calculation and application of waste, only 13,2% TmNOEst, when the incorporation of sewage sludge, was below the 20% recommended in Resolution Nº 375/2006 of CONAMA. Other mineralization rates found were higher than the NO mineralization rate established minimum in CONAMA Resolution Nº 375/2006 to LE digested anaerobically. Variations in rates of mineralization and NO COfo, the constant of decomposition of COfo (kc) and the constant accumulation of nitrogen (kN) were associated with the application form of the residue in the soil (as incorporated or surface) and the form of sampling performed.