Banca de DEFESA: MARCELLE PORTÃO MORGADO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MARCELLE PORTÃO MORGADO
DATE: 30/05/2023
TIME: 14:00
LOCAL: sala 24 do departamento de solos
TITLE:

Structural quality of humified matter in different management systems in sandy and loamy textured soils accessed by spectroscopic techniques.

KEY WORDS:

Spectroscoppy. Management systems. Humic substances.

PAGES: 55
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SUMMARY:

The structural quality of humified organic matter can be assessed through spectroscopic techniques that allow us to analyze the chemical and structural properties of soil organic matter, providing information about its composition and stability. In sandy soils, where the nutrient and water retention capacity is generally lower, soil management can influence the structural quality of humified organic matter in various ways. In clayey soils, where the nutrient and water retention capacity is higher, soil management can also influence the structural quality of humified organic matter. Spectroscopic techniques indicate a greater presence of stable chemical bonds and functional groups associated with increased organic matter stability, enabling a better understanding of the effects of soil management on the formation and preservation of humified organic matter. Thus, the objectives of this study were to characterize the quality of soil organic matter through the extraction of humic substances: humic acids, fulvic acids, and humins in clayey and sandy soils under different management systems using spectroscopic techniques. Three managed areas and one reference area without anthropogenic action were evaluated in two experimental areas located in different locations and biomes, namely: an experimental area located in Terra Roxa-PR, with 25 years of no-tillage, 19 years of no-tillage, 45 years of conventional tillage, and vegetation from the Atlantic Forest biome, and an experimental area located in Uberaba-MG, with 6 years of no-tillage, 18 years of no-tillage, 20 years of conventional tillage, and vegetation from the Cerrado biome. All humic substances were obtained using the methodology of the International Humic Substances Society (IHSS), and ¹³C NMR CP MAS spectra were recorded under the same experimental conditions. The spectra were evaluated using ACD/Labs 2020 1.1 software. For chemometrics, the spectra underwent principal component analysis (PCA), multivariate curve resolution (MCR), and descriptive analyses using The Unscrambler software (version 10.4). The study concluded that the structural quality of humified matter is modified depending on the type of soil management adopted, the management time, and the soil texture. Agricultural practices associated with the duration of adoption directly influence the quantity and quality of organic matter, as well as its stability.

COMMITTEE MEMBERS:
Presidente - 1399485 - ANDRES CALDERIN GARCIA
Externa à Instituição - CLÁUDIA POZZI JANTALIA - EMBRAPA
Interno - 1060711 - MARCOS GERVASIO PEREIRA