Banca de DEFESA: FRANCISCO XIRLEAN XAVIER ALVES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : FRANCISCO XIRLEAN XAVIER ALVES
DATE: 02/04/2024
TIME: 09:00
LOCAL: Sala 24 do Departamento de Solos
TITLE:

Characterization of physical, chemical and microbiological attributes in gullies in the Atlantic Forest Biome

KEY WORDS:

Atlantic Forest Biome; Soil quality indicators; Erosion processes.

PAGES: 118
BIG AREA: Ciências Agrárias
AREA: Engenharia Agrícola
SUBÁREA: Engenharia de Água e Solo
SPECIALTY: Conservação de Solo e Água
SUMMARY:

Water erosion is one of the forms of degradation that most affects tropical areas around the world, causing environmental, social and economic impacts. One of the main causes of this type of degradation is the removal of the vegetation covering the topsoil. In Brazil, the Atlantic Forest Biome is heavily affected by this type of erosion process due to high rates of deforestation and high rainfall, causing the most advanced stage of water erosion, gullies. The aim of this study was to characterize the physical, chemical and microbiological attributes of the soil in gullies with different degrees of evolution in the Atlantic Forest Biome. Four gullies were selected according to each evolutionary stage set out in the literature, namely: a) initial (IN), b) intermediate (INT), c) mature (MA) and d) senile (SE). Deformed and undeformed soil samples were collected from the 0.0-0.10 layer on the external (ext) and internal (inte) sides of the gullies. Physical, chemical and microbiological soil attributes were assessed at the end of the dry season. Based on the results of the aforementioned analyses, it was possible to observe that the soil's physical attributes showed higher levels of natural clay and sand in the SE stage. The bulk density (Bd) and total porosity (Tp) attributes, on the external and internal faces, respectively, were also higher in the SE stage. For the stability of microaggregates, there was a tendency towards balance between the faces for the variables water-dispersible clay (WDA), non-water-dispersible clay (WND) and water-reflocculable clay (WRA). For the chemical attributes, higher levels of hydrogenionic potential (pH), calcium (Ca²⁺), magnesium (Mg²⁺), potassium (K⁺), phosphorus (P), S-value, T-value and V-value were observed in the gully with a higher stabilization stage. The fractions of organic matter, total organic carbon (TOC), particulate organic carbon (POC), organic carbon associated with minerals (COam) and oxidizable carbon (POXC), followed the same pattern as the attributes related to fertility. Observation of the data on total carbon (TC), total nitrogen (NT) and the C/N ratio showed higher values in the SE gully and a tendency towards balance between the faces. For the microbiological attributes, the highest levels of soil protein related to total glomalin - PSGR-T, activity of the enzyme β-glucosidase, as well as species richness, were observed in the gully in the senile stage. A total of 23 morphospecies were quantified, distributed at species (17) and genus (6) level, with a predominance of the genera glomus (6 species) and acaulospora (5 species). As for the multivariate analyses, there was a greater correlation between the soil organic matter attributes and the soil microbiological attributes. It can be concluded that the physical, chemical and microbiological attributes of the soil in gully environments in the Atlantic Forest biome are influenced by the evolutionary stages and their respective surface faces, in the 0-0.10 cm layer, with the senile stage showing the best soil conditions for recovery, especially on the inner face for most of the soil attributes. This is due to the evolutionary stage, i.e. from the moment regeneration occurs with the colonization of plant species inside the gully, the degradation process slows down and the ecosystem begins to stabilize the soil's systemic activities. The attributes used functioned as indicators of soil quality in these environments, reflecting the dynamics of the edaphic attributes and providing information that can support the design of programs aimed at recovering degraded areas.

COMMITTEE MEMBERS:
Presidente - 1060711 - MARCOS GERVASIO PEREIRA
Interno - 2131822 - CONAN AYADE SALVADOR
Externa à Instituição - ELIANE MARIA RIBEIRO DA SILVA - EMBRAPA