Banca de DEFESA: EDILSON AMARAL TAVARES COUTINHO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : EDILSON AMARAL TAVARES COUTINHO
DATE: 28/02/2023
TIME: 09:00
LOCAL: meet.google.com/zha-zyau-dvd
TITLE:

STRUCTURAL QUALITY IN SOILS CULTIVATED WITH SUGARCANE AS A FUNCTION OF HARVESTING METHOD

KEY WORDS:
PAGES: 63
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Física do Solo
SUMMARY:

Sugarcane is one of the most relevant crops in Brazil, mainly because of its great economic importance. With an estimated production of 596.1 million tons in the 2022/2023 harvest, the Brazilian sugarcane agroindustry is an important global exporter of sugar and alcohol. To improve the profitability of the sector, circumvent the labor shortage, and comply with environmental legislation, in the production process, total or partial mechanized harvesting about the traditional method, with previous burning of the sugarcane plantation, has presented itself as the best option, from the economic and environmental quality point of view. From the physical attributes of the soil, it is possible to measure its quality, when modified by different agricultural systems, and to guide management strategies and maintenance of the physical quality of the soil, avoiding its degradation. The objective of this study was to evaluate the structural physical quality of the soil in areas under sugarcane cultivation, with mechanized harvesting systems (raw sugarcane) and previous burning of the sugarcane field. The soil samples for the physical tests were collected in structured (aggregates and volumetric cylinder) and unstructured (auger/shovel: fine air-dried soil - FADS) forms. Thus, the aggregate samples were used to determine the tensile strength of the soil (TS), via bench penetrometer; as well as for the aggregate stability index (ASI) tests, via the wet method. The aggregates for TS were moisture balanced at room temperature; while the aggregate stability parameters (weighted mean diameter, geometric mean diameter, and aggregate stability index) were determined using the Yoder apparatus. Samples in the volumetric cylinder (≅ 100 cm³) were used in the tests of total porosity (saturation method), pore size distribution (macro and micropores, via tension table), and soil density (volumetric cylinder method). In contrast, those in FADS were used to determine particle size and organic carbon of soils. In the aggregates assays two size groups were used, each with three equivalent diameter classes (eq.), being: the first group, measuring 22 and 44 mm, used in the TS assays; and the second, with 5.32; 11.5, and 17.6 mm, for the ASI ones. Each aggregate size class was also used in the tests to determine the representative elemental volume (REV), defined for each attribute studied (TS and ASI). Thus, the delimitation of the REV was based on the size of the aggregate, from which the increase in its volume did not influence the results of the analyzed attribute. Thus, this research found that harvesting under burning promoted changes in the structure of the soil, even on a short time scale, represented by the burning of the vegetation cover in the environment and consequently reducing soil organic matter (SOM), the native forest area presented the best structural values being followed by the cane area without the burning process. The REV was kept in standard sizes (5.32 mm for the wet tests and 22 mm for the TS tests) following the standard established in the literature.

COMMITTEE MEMBERS:
Presidente - BRIVALDO GOMES DE ALMEIDA
Interno - ADEMIR DE OLIVEIRA FERREIRA
Externo à Instituição - JAEDSON CLÁUDIO ANUNCIATO MOTA - UFC