Banca de DEFESA: PEOLA REIS DE SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : PEOLA REIS DE SOUZA
DATE: 23/02/2024
TIME: 08:30
LOCAL: Por videoconferência
TITLE:

"DIAGNOSIS, MONITORING AND MITIGATION OF COMPACTION IN SOILS CULTIVATED WITH OIL PALM IN THE EASTERN AMAZON"

KEY WORDS:

Organic matter; Precompression stress; Range of water contents for tillage; Soil compression; Soil moisture.

PAGES: 148
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUMMARY:

Oil palm produces one of the most demanded oils in the world, and its management requires mechanized operations, from soil preparation to periodic fruit harvesting, which can lead to soil compaction. The general objective of this research was to characterize soil physical properties for the diagnosis, monitoring, and proposal of mitigation measures for soil compaction in oil palm plantations. The specific objectives are (i) to estimate the range of water content limiting the compress process induced by mechanized operations; (ii) quantify the effects of plantation age, management zones and temporal variation on penetration resistance (PR) and aeration porosity (AP); (iii) select a representative equation for diagnosis and prevention of compress risk; (iv) evaluate the decomposition and mineralization of oil palm residues; (v) analyze the contribution of oil palm residues to the physical fractions of organic matter and the availability of macronutrients; (vi) establish the pre-consolidation pressure (σp) and compression index (CI) in sandy and clayey soil with empty fruit bunches (EFB) on the surface. The study was conducted in three plantations (1999, 2013, 2017), where soil samples were collected in three management zones (crow, planting line and traffic line). The water contents at the soil preparation limits were estimated using van Genutchen parameters. The spatial and temporal variation of PR and AP was monitored over twelve months. A factorial incubation experiment was conducted under controlled conditions (4 residues (Petiole, Leaflets, EFB, MIX) x 6 time – (0, 0,04, 0,08, 0,12, 0,16, 0,22 e 0,30 year)) + 1, distributed in four blocks. The C-CO2 emission flux, remaining dry mass of the residue (msR), nutrient and half-life of the residue were calculated. Uniaxial tests were carried out in a factorial design (2 initial bulk density - BDi x 5 quantities of EFB on the surface (0, 20, 40, 60, 80 Mg ha-1 )), with 4 repetitions. The σp and CI were taken from the compression curve. In general, the highest limiting water contents occurred in the planting line and the lowest in the traffic zone. Organic carbon and bulk density influence the range of water content for tillage. The temporal variation in soil moisture influenced the production of fresh bunches and lower PR values. The age of the plantations had a greater impact on PR than AP. In the rainiest trimesters, the soils had AP below the critical limit (10%). Accumulated C-CO2 emissions were higher in the soil with residue. There was immobilization of nitrogen in the soil, and potassium showed greater mineralization. The residues had no impact on the carbon in the soil fractions. The application of 40 Mg ha-1 of EFB led to an increase in σp in the sandy soil and the CI showed that low initial bulk density increases susceptibility to soil compaction. Evaluations over time have made it possible to identify compress processes, which can be minimized by managing EFB in the soil.

BANKING MEMBERS:
Externo à Instituição - TEOGENES SENNA DE OLIVEIRA - UFV
Presidente - 1551186 - HERDJANIA VERAS DE LIMA
Externa à Instituição - LORENA CHAGAS TORRES - SLU
Externo à Instituição - MICHEL KEISUKE SATO - IFPA
Externa à Instituição - SUELI RODRIGUES - UFPI