Banca de QUALIFICAÇÃO: MARIA CAROLINE AGUIAR AMARAL

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : MARIA CAROLINE AGUIAR AMARAL
DATE: 06/06/2024
TIME: 14:30
LOCAL: sala virtual: https://meet.google.com/oyg-zbjf-vfm
TITLE:

SOIL AGGREGATES AND THEIR RELATIONSHIP WITH EDAPHIC MACROFAUNA IN COCOA CULTIVATION SYSTEMS AND NATIVE FORESTS

KEY WORDS:

Soil quality, cocoa farming, cover crops

PAGES: 28
BIG AREA: Outra
AREA: Ciências Ambientais
SUMMARY:

Land use changes have been linked to climate change and soil degradation phenomena, primarily through the conversion of forest areas to agricultural crops. In this regard, it is necessary to understand the dynamics and effects of these changes on soil aggregate formation, as well as the behavior of edaphic macrofauna, and how these are interrelated. The cocoa tree (Theobroma cacao L.) is a crop of socio-economic importance worldwide, and its cultivation, traditionally in agroforestry systems, has been implemented in dense, full-sun systems in various regions of the globe, including Brazil. Given this, we hypothesize that soils cultivated with full-sun cocoa systems in conjunction with cover crops promote the establishment of edaphic communities, aggregate formation, and soil carbon accumulation, similar to that of a regenerating forest. Therefore, this study aimed to investigate soil carbon, the genesis of aggregates, and their relationship with edaphic macrofauna in full-sun cocoa cultivation systems associated with cover crops and in agroforestry systems. The study is being conducted in the Atlantic Forest biome, examining seven land use systems, namely: three full-sun cocoa systems associated with cover crops (forage peanut, Brachiaria, and spontaneous plants); one full-sun cocoa system without cover crops; two agroforestry systems (cocoa with Erythrina and cocoa with caja); and a fragment of regenerating forest (reference treatment). The study was conducted in cocoa cultivation systems located at the Cocoa Research Center (CEPEC), a research unit of CEPLAC (Executive Commission of the Cocoa Farming Plan), situated in the municipality of Ilhéus, BA (14º 45’ 64” S 30º 14’ 32” W). In each of the systems, four fixed repetitions (30 x 30 m), homogeneous in terms of slope, soil use history, plant density, and edaphic characteristics, called plots, were determined, spaced 100 m apart, totaling 28 plots. Soil collections were made for analyses of soil macrofauna, relative contribution and pathways of aggregate and fine roots formation, in the 0-10 cm layer. In the full-sun cocoa cultivation system associated with Brachiaria, the highest average percentage value of soil aggregate contribution for the fraction larger than 6mm was observed, while in the agroforestry system with Erythrina, the lowest average value for this variable was observed. A similar result was observed when evaluating the weighted average diameter.

COMMITTEE MEMBERS:
Interna - 3025873 - KHETRIN SILVA MACIEL
Interno - 1099329 - JOAO CARLOS MEDEIROS
Externa à Instituição - CRISTIANE FIGUEIRA DA SILVA - UFRRJ
Externa à Instituição - MARIA SUELI HEBERLE MAFRA
Externo à Instituição - FLÁVIA FERREIRA DE CARVALHO - UESB
Externo à Instituição - Julian de Jesus Lacerda - UFPI
Externa à Instituição - ADRIANA DIAS CARDOSO - UESB
Externo à Instituição - PAULO HENRIQUE MARQUES MONROE - UESB
Externo à Instituição - FABRICIO VIEIRA DUTRA - UESB