Banca de DEFESA: EMANUELLE MARIA DA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : EMANUELLE MARIA DA SILVA
DATE: 28/03/2022
TIME: 14:00
LOCAL: Defesa remota pelo Google Meet
TITLE:

Recovery of degraded soil in the semiarid region of Pernambuco by the cultivation of native species and Atriplex nummularia

KEY WORDS:

Caatinga. Desertification. Salt affected soils. Ksat. Tolerance mechanisms. Enzymatic activity.

PAGES: 125
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SUMMARY:

Land use changes have caused degradation of extensive areas in the semiarid region of Northeast Brazil. Associated with low rates and poor distribution of rainfall and high evapotranspiration, this can favor the accumulation of salts in soil, by stressors for plants and increasing the desertification risk. With the revegetation of these areas, it would be possible to maintain the environmental balance in this ecosystem that is so susceptible to degradation. Native species, due to their high degree of resilience, have potential for use under water and saline stress conditions, in addition to being an important regulator of climate, biodiversity, biogeochemical cycles and the physical, chemical and biological properties of the soil, however few studies are carried out with these, mainly under field conditions and regarding their biochemical responses to attenuate abiotic stresses. Thus, with the objective of evaluating the potential of native species in the recovery of a saline soil in the semiarid region of Pernambuco, an experiment was set up in randomized blocks, with eight treatments (cultivation of six native species and Atriplex nummularia L., and the treatment without cultivation of plant) in four replications. Soil samples were collected at different times, totaling 48 months of follow-up, at different depths (0-5, 5-25 and 25-50 cm) to assess changes in physical and chemical soil attributes, and 0-20 cm for evaluate changes in microbiological attributes. And leaves were collected from the middle third of the plants, for biochemical analysis at the end of field monitoring . The results were subjected to analysis of variance and when significant, their means were tested by Tukey's test (p < 0.05) and Pearson's correlation coefficient was calculated to identify relationships between salinity and biological attributes of the soil. The results showed that the use of Caatinga tree species, such as Catingueira, Mulungu and Pau Ferro, were more efficient in improving the physical attributes of the soil, especially hydraulic conductivity (Ksat) and porosity (P), improving soil permeability. Electrical conductivity (EC), sodium adsorptium ratio (SAR) and exchangeable sodium percentage (ESP) values remained above those used to classify soils as saline and/or sodic, indicating that no species was efficient in attenuating soil salinity, requiring more time to be monitored. Exchangeable Na+ and EC may negatively affect total organic carbon (TOC) content and the activity of β-Glucosidase and Urease enzymes. Native species can adapt to salinity, presenting an efficient enzymatic and non-enzymatic defense system, and in this study they performed better than Atriplex nummularia. Umbuzeiro presented the most efficient enzymatic antioxidant defense system, with high production of superoxide dismutase (SOD), catalase (CAT) and ascorbato peroxidase (APX) enzymes, while Aroeira and Pau-Ferro presented a more efficient non-enzymatic antioxidant defense system, accumulating proline and soluble carbohydrates that help in the osmotic adjustment.

BANKING MEMBERS:
Presidente - 1348548 - MARIA BETANIA GALVAO DOS SANTOS FREIRE
Interno - 1350517 - MATEUS ROSAS RIBEIRO FILHO
Interna - 1929733 - GISELLE GOMES MONTEIRO FRACETTO
Externo ao Programa - 2171151 - LUIZ GUILHERME MEDEIROS PESSOA
Externo à Instituição - HIDELBLANDI FARIAS DE MELO - UFV