Banca de DEFESA: FRANCISCO MARTO DE SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : FRANCISCO MARTO DE SOUZA
DATE: 29/11/2023
TIME: 14:00
LOCAL: Prédio Prof. Mateus Rosas Ribeiro
TITLE:

Soil quality subjected to different forms of use in Cariri Paraibano

KEY WORDS:

Soil quality index. Semiarid. Grass. Soil attributes.

PAGES: 95
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SUMMARY:

The soils of the semi-arid region are going through a process of natural degradation, but enhanced by human action. However, it is difficult to measure/quantify this degradation, based on a standard quality index. With this, the objective was to generate a Soil Quality Index (IQS) when subjected to different forms of use, integrating physical, chemical and biological attributes in Cariri Paraíba, in Taperoá-PB. Four areas were chosen that were being subjected to different forms of use: irrigated tifton grass (CI), forage cactus (PA), rainfed buffel grass (CB) and riparian forest (MC). Nine composite soil samples were collected from each form of land use, in the surface layer (0-20 cm), to evaluate chemical, physical and biological attributes. The chemical attributes evaluated were: pH, EC, PST, Ca2+, Mg2+, K+, Na+, (H + Al), SB, T, V, Cu2+, Fe2+, Mn+, Zn+ and B. The physical attributes evaluated were: coarse sand (AreiaG), fine sand (AreiaF), silt, clay, soil density (Ds), particle density (Dp), clay dispersed in water (ADA), degree of flocculation (GF) , degree of dispersion (GD), aggregate stability index (IEA), aggregates larger than 2 mm (AGRI), total porosity (Pt), mean measured diameter (DMP), geometric mean diameter (DMG), macroaggregates (MacroA, mesoaggregates (MesoA) and microaggregates (MicroA).The biological attributes evaluated were: total organic carbon (TOC), soil microbial biomass carbon (C-BMS), soil microbial biomass nitrogen (NBMS), carbon/ microbial biomass nitrogen (C-BMS/N-BMS), soil basal respiration (RBS), metabolic quotient (qCO2) and microbial quotient (qMiC). The data were subjected to the Shapiro-Wilk normality test and homogeneity of variance tests with Levene's test. After a preliminary analysis, the need for parametric analysis such as ANOVA and Tukey test was noted. A principal component analysis (PC) was carried out and the IQS was established for all areas with different land uses, considering the chemical, physical and biological attributes separately, in addition to establishing the IQS considering all attributes together. A classification was also generated for the IQS, assigning interpretations as low, medium and high. The IQS was most influenced by physical attributes, especially those that are more directly impacted by chemical attributes, such as salinity indicators (EC, PST and Na+). Therefore, the IQS was more dependent on the structure and degree of dispersion of the soil. The areas occupied by buffel grass and cactus presented IQS equal to and greater than 0.9, respectively. The area irrigated with tifton grass presented the lowest IQS, suggesting that these areas in semi-arid soils are adequately monitored, mainly due to the chemical quality of the water used in irrigation, linked to good management of organic matter. In all areas, biological attributes had little influence on the IQS, suggesting that the use of organic matter is a mandatory condition for whatever land use in the semi-arid region. The joint assessment of chemical, physical and biological attributes better reflects the “status” of the soil and is more appropriate for establishing its quality index, suggesting that these attributes be interpreted in a contextualized way, for a more adequate assessment of land use. The IQS of all areas with their different uses was considered high, when the chemical, physical and biological attributes were jointly evaluated, suggesting that the uses are being adequate in the studied environment, as long as the organic matter management recommendations are observed, recommended to these semi-arid environments in a continuous and dynamic way.

COMMITTEE MEMBERS:
Presidente - FERNANDO JOSE FREIRE
Interna - GISELLE GOMES MONTEIRO FRACETTO
Externo à Instituição - JEFREJAN SOUZA REZENDE
Externa à Instituição - PAULA RENATA MUNIZ ARAUJO - UFRPE
Interno - YGOR JACQUES AGRA BEZERRA DA SILVA