Banca de DEFESA: NELIA DALUVIA RAFAEL CAMBANHANE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : NELIA DALUVIA RAFAEL CAMBANHANE
DATE: 28/02/2025
TIME: 09:00
LOCAL: Departamento de Agrotecnologias e Sustentabilidade
TITLE:

CARBON AND NITROGEN STOCKS AND DEGREE OF C STABILIZATION IN SOIL UNDER DIFFERENT SUSTAINABLE AGRICULTURAL MANAGEMENT SYSTEMS IN THE CERRADO

KEY WORDS:

particulate organic carbon, organic carbon associated with minerals, crop-livestock integration, agroforestry systems

PAGES: 55
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Manejo e Conservação do Solo
SUMMARY:

The capacity of soils to act as one of the largest C reservoirs depends on the balance between C inputs and outputs, and is directly related to changes in land use and agricultural management systems. This study aimed to evaluate soil carbon and nitrogen stocks, as well as the forms of C found in the soil (labile and stable) in different sustainable agricultural production systems and in an area under native Cerrado vegetation, in João Pinheiro (MG). The study was conducted on a farm located in the municipality of João Pinheiro, belonging to the Paracatu microregion, in the northwest of Minas Gerais. Three distinct soil management systems were evaluated, namely: productive pasture, crop-livestock integration, agroforestry system, and native forest. Monitoring of carbon (C) and nitrogen (N) in the soil was conducted following the guidelines of the Measurement, Reporting, and Verification Protocol. To quantify C and N contents, soil bulk density (SD), chemical analyses (Ca+2, Mg+2, Al+3 and pH in water), physical analyses (granulometry) and physical fractionation, trenches were dug and undisturbed and disturbed soil samples were collected. Soil samples were collected at the following depths: 0-5, 5-10, 10-20, 20-30, 30-40, 40-60, 60-80 and 80-100 cm. The study was carried out using a completely randomized experimental design. The MN forest exhibited the lowest SD values at all depths analyzed, differing significantly from the managed systems. This condition reflects the natural state of the soil, characterized by high organic matter content, good porosity and absence of intensive management. The MN presented higher C stock values at all depths analyzed, except in the ILP, which was statically equal. The N stocks presented higher and statistically equal values in the PP and ILP management systems, and the lowest values were observed in the SAF at all evaluated depths. It was observed that the SAF and ILP presented the highest COP accumulation in the surface layer (0-5 cm), with a value of 1.8 Mg ha⁻¹. The MN presented a higher COAM contribution in relation to the management systems, presenting a higher value of 20.32 Mg ha-1 in the 0-5 cm layer. This result is important because it shows that the carbon in the soil is protected in organo-mineral complexes. The removal of MN for the implementation of PP preserves the C stocks in the soil only in the surface layer of the soil. On the other hand, ILP maintains the C levels in the soil at the same level as the MN, showing that it is an adequate management system for maintaining soil quality.

COMMITTEE MEMBERS:
Presidente - 1740899 - ERIKA FLAVIA MACHADO PINHEIRO
Externo à Instituição - ALDAIR DE SOUZA MEDEIROS - UFPI
Externa à Instituição - ANA CAROLINA DE SOUZA FERREIRA