Banca de DEFESA: JOÃO ANTÔNIO MONTIBELLER FURTADO E SILVA
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.DISCENTE : JOÃO ANTÔNIO MONTIBELLER FURTADO E SILVA
DATA : 24/01/2019
HORA: 09:00
LOCAL: Sala 24 do PPGA-CS
TÍTULO:
Humic Substances Structural Evolution and Interactions Mechanisms with Heavy Metals in a Typic Haplupox Treated with Pig Slurry
PALAVRAS-CHAVES:
Soil organic matter, Fulvic and humic acids, Toxic metals.
PÁGINAS: 130
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Ciência do Solo
RESUMO:
The pig slurry applied to the soil reduce costs with fertilizers and water pollution risks. The pig farming is concentrated in producing regions, where the pig slurry is the main residue generated, and its application on soil play a role in soil organic matter characteristics and in heavy metals and phosphorus dynamics. Recently, has been reported the role of pig slurry characteristics in soil heavy metals mobility and bioavailability by the formation of stables soluble complexes. However, many questions still are unanswered. Thus, the present thesis aims to evaluate the alterations in soil humic substances structure induced by pig slurry systematic application over time. As well as understanding the mechanism of organic structures incorporation to soil humic substances, and its interactions mechanisms with heavy metals and phosphorus. To reach these goals, a Typic Hapludox subjected to systematic applications of pig slurry doses (0, 50, 100 m³ ha-1 application-1), over six years (2009 – 2015), and cultivated with corn (Zea mays), simulating silage, on the summer time, and black oat (Avena strigosa Schreb.) and Italian rye grass (Lolium multiflorum Lam.) consortium, as cover crop, on winter time. Soil samples were collected by the years 2011, 2014 and 2015, of wich organic matter was chemically fractionated in fulvic acids, humic acids and humin. These fractions were quantified and characterized by their spectroscopic characteristics (CP MAS 13C-RMN, FTIR e UV-vis), elementary composition (C, H, N, O e S) atomic relations (C/N, H/C, O/C), heavy metals (Cu, Zn, Pb e Ni) and phosphorus levels. Were also evaluated the heavy metals pseudototal levels in six soil layers (0-2,5; 2,5-5; 5-10; 10-20; 20-40, e 40-80 cm), and bioavailable heavy metals and phosphorus (P- total, P-Melich e P-remaining) levels in superficial soil layer ( 0-20 cm). The heavy metals and phosphorus accumulation in plants tissues were quantified. And other materials as the ration given to the pigs generators of the slurry and the pig slurry used in the experiment itself was samples and analyzed for their heavy metals levels. All evaluated heavy metals were found in the ration and the slurry, evidencing the origin of these elements in the system. The pig slurry has shown mainly aliphatic and functionalized organic structures, with high capacity of formation of soluble complexes with heavy metals. When these aliphatic structures are added to the soil, they are initially incorporated to the fulvic acids, than subsequently evolve to humic acids. These structures presented relation with heavy metals and phosphorus mobility and bioavailability in soil by different mechanisms. Over application time, the soil humic substances, mainly the fulvic acids, acquires pig slurry structural characteristics, such as low aromaticity and functional oxygenated group abundance. There was an increase in the incorporation of heavy metals to the humic substances as long as were incorporated more aliphatic organic structures to fulvic and humic acids. However, the phosphorus presented a different dynamics, was not incorporated to fulvic and humic acids, even with the increase of its total levels. This element was kept in labile forms, mainly due to the reduction of soil fixation.
MEMBROS DA BANCA:
Externo à Instituição - ADEMIR FONTANA - EMBRAPA
Externo à Instituição - ARCANGELO LOSS - UFSC
Externo ao Programa - 1412091 - ERICA SOUTO ABREU LIMA
Interno - 2213075 - EVERALDO ZONTA
Presidente - 387263 - NELSON MOURA BRASIL DO AMARAL SOBRINHO