Banca de QUALIFICAÇÃO: LOREN CHISTÉ

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE: LOREN CHISTÉ
DATA: 25/07/2024
HORA: 08:00
LOCAL: Anfiteatro DCS02
TÍTULO:

Synthesis of biochar-based fertilizers: boron and copper release kinetics and their agronomic value for eucalyptus and wheat

PALAVRAS-CHAVES:

organometallic complexes, fertilizer composites, biochar-micronutrient composites, micronutrient release kinetics.

PÁGINAS: 20
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Ciência do Solo
ESPECIALIDADE: Fertilidade do Solo e Adubação
RESUMO:

Biochar is a byproduct of pyrolysis, with its elemental composition depending on the biomass used and the pyrolysis temperature. Due to the scarcity and high cost of micronutrients, the use of biomass rich in B and Cu, which can be complexed into the organic matrix of biochar, is a promising strategy to meet the nutritional demands of eucalyptus and wheat. This study had three main objectives: i) to produce and characterize biochars from different biomasses combined with soluble and less soluble sources of B and Cu under varying pyrolysis temperatures; ii) to investigate the release kinetics of B and Cu and their effects on the availability and residuality of micronutrients in contrasting soils; iii) to evaluate the agronomic value and efficiency of biochar-based composites in the cultivation of eucalyptus and wheat. The study was divided into two experiments. The first involved the production of B-doped biochar composites from chicken manure, sewage sludge, and shrimp residue, pyrolyzed at 300 and 550°C. Characterization included pH, electrical conductivity, volatile matter, ashes, fixed carbon, carbon, nitrogen, C/N ratio, scanning electron microscopy, release kinetics in 2% citric acid, and the application of the best composites in eucalyptus cultivation in a greenhouse using two contrasting Oxisols. The experimental design was completely randomized, in a 3x2x2 factorial scheme, with three replicates, comparing negative and positive controls. The second experiment followed the same procedures but used Cu as the micronutrient and wheat as the crop. As results, Fourier Transform Infrared Spectroscopy (FTIR) analysis confirmed successful B integration and interaction with organic matrices, highlighting functional groups responsible for composite properties. This facilitated the development of highly predictive Partial Least Squares (PLS) regression models (R²pred ~ 0.8). The FSC-BA composite at 300 °C showed notable thermal stability, B retention, and availability, enhancing B release kinetics. FTIR analysis confirmed the incorporation of Cu into the biochar, highlighting significant adsorption patterns and the presence of functional groups such as OH, C=O, C-O-C, and SO4²- in the sewage sludge composite doped and pyrolyzed with copper sulfate at 550 °C (CSS/CS-5). The CSS/CS-5 composite demonstrated superior agricultural performance compared to pure copper sulfate, reducing Cu release into water and enhancing Cu accumulation in wheat shoots. In Oxisols, CSS/CS-5 maintained low Cu concentrations, indicating controlled release that meets wheat's high Cu nutritional demands. The residual effect was more significant in soil samples treated with copper sulfate across both soil types. The biochar-based composites were effective in supplying micronutrients to eucalyptus and wheat crops, meeting nutritional demands comparable to commercial soluble mineral sources. The production of B- and Cu-rich composites presents a viable strategy to partially or totally replace commercial mineral micronutrient sources.

MEMBROS DA BANCA:
Interno - MARCO AURELIO CARBONE CARNEIRO (Membro)
Externo à Instituição - KEIJI JINDO - UFLA (Suplente)
Interno - FLAVIO HENRIQUE SILVEIRA RABELO (Membro)
Presidente - FELIPE HAENEL GOMES (Membro)
Interno - CYNTHIA DE OLIVEIRA - UFLA (Membro)