Banca de QUALIFICAÇÃO: OTAVIO AUGUSTO QUEIROZ DOS SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : OTAVIO AUGUSTO QUEIROZ DOS SANTOS
DATE: 12/10/2020
TIME: 09:00
LOCAL: Impacto do manejo agrícola em Organossolos no estado do Rio de Janeiro
TITLE:

Impact of agricultural management in Histosols in the state of Rio de Janeiro.

KEY WORDS:

Land use. C and N stocks. P sequential fractionation. Subsidence.

PAGES: 10
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Manejo e Conservação do Solo
SUMMARY:

Histosols are soils with high levels of organic matter and responsible for storing carbon and nitrogen, important in the formation of greenhouse gases (GHG). Proper management preserves organic matter and, consequently, mitigates GHG production. The aim of the study was to evaluate changes in the properties of Histosols; content of organic matter and sulfate, stocks of C and N, availability and content of the fractions of P, depending on the soil turning and artificial drainage. For this study, three areas were selected: secondary forest in natural regeneration, conventional cultivation of cassava (Manihot sculenta) and intercropped coconut (Cocos nucifera) with cassava, in which profiles were opened and description and sample collection were carried out. Chemical characterization, von Post scale of decomposition of organic matter, percentage of rubbed fiber, organic matter content, percentage of mineral material, soil density, electrical conductivity, soluble sulfate, total organic carbon (TOC) and total nitrogen (NT), chemical fractionation of organic matter and C and N stocks and sequential fractionation of P. The results of chapter I show that the values of COT and NT decreased 33 and 20%, respectively, in the histic horizon in the area with cassava cultivation. In the area of coconut intercropped with manioc, the TOC and NT values decreased by 31 and 18%, respectively, in the histic horizon. There were also losses of labile organic carbon and development of the sulfidization process. The results of Chapter II show that in the cassava cultivation area there was a reduction in the total P content of the soil in subsurface by 35.6 and 37.9%, when compared to the coconut cultivation area intercropped with cassava and with the area of forest, respectively. In all areas there was a predominance of the fraction of highly recalcitrant residual P (> 70%) in the total P content of the soil. The available P content was reduced only in the cassava cultivation area. Soil drainage and turnover reduced the stocks of C and N in the soil and also, in the P adsorption and mineralization processes, affecting all of its inorganic fractions.

BANKING MEMBERS:
Presidente - 1060711 - MARCOS GERVASIO PEREIRA
Externo à Instituição - ARCANGELO LOSS - UFSC
Externo à Instituição - JOLIMAR ANTONIO SCHIAVO