Banca de DEFESA: ARNALDO JOAQUIM DE SOUZA JUNIOR

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ARNALDO JOAQUIM DE SOUZA JUNIOR
DATE: 27/02/2024
TIME: 09:00
LOCAL: Auditório
TITLE:

DYNAMICS OF POLYACRYLAMIDE IN CONTRASTING COHESIVE SOILS UNDER THE EFFECT OF SILICON APPLICATION 

KEY WORDS:

Silicate fertilization. Tabuleiros Costeiros. Cristalino Meridional. Soil hydraulic properties. Polymer adsorption.

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

Cohesive soils, or with a cohesive character, are soils that have horizons or subsurface layers that harden significantly when dry, presenting a generally massive structure; however, when they are moistened they quickly return to their friable state. Such soils occur in areas of great socioeconomic importance and are widely used in agriculture; however, in cohesive horizons, root depth is limited, which reduces water and nutrient absorption by plants. These limitations are a consequence of changes in soil matric potential and soil resistance to root penetration. The alternatives to deal with the cohesion of these soils are sometimes similar to those applied to reduce soil compaction, such as scarification and subsoiling. However, these alternatives result in the formation of compacted layers in the subsurface (plowfoot), which end up worsening the erosion problem and limiting root development. In this context, polyacrylamide (PAM) has been used as an erosion control and soil conditioning agent; however, a better understanding of its transport is necessary to enhance its effects on reducing cohesion in soils. Information regarding PAM transport in the soil environment, specifically in cohesive soils, is still limited, with gaps regarding the modeling and determination of transport parameters and knowledge of the factors that affect its movement through the soil. Given this, the research aimed to investigate the interaction between polyacrylamide (PAM), the extraction of cementing agents, and silicate fertilizer in cohesive soils, with a focus on evaluating how these elements influence the mobility of PAM. The research was conducted in different geosystems - the Tabuleiros Costeiros (under Argissolo Amarelo Distrocoeso epirredóxico) and the Cristalino Meridional (under Latossolo Amarelo Distrocoeso) - where the physicochemical and mineralogical properties of the soils were evaluated to understand their influence on PAM mobility. Using the Sips isotherm model to model adsorption and the Attenuation Factor to analyze the persistence of PAM in the soil, the study integrates chemical, physical, and mineralogical analysis methods for a comprehensive understanding of the process. Treatments were applied, including the addition of silicate and the removal of cementing agents, to evaluate their influence on PAM adsorption. The research demonstrated that the hydraulic, chemical, and mineralogical properties of the soil strongly influence the mobility of PAM in the studied soils. Furthermore, silicate treatments have proven effective in improving PAM penetration, especially in cohesive horizons, highlighting the need to adopt integrated approaches that simultaneously consider soil chemical, physical, and mineralogical interactions to optimize PAM effectiveness. These findings expand understanding of the use of PAM in agricultural practices and pave the way for more efficient and sustainable soil management methods.

COMMITTEE MEMBERS:
Presidente - BRIVALDO GOMES DE ALMEIDA
Interno - VALDOMIRO SEVERINO DE SOUZA JUNIOR
Externo à Instituição - JOSÉ MIGUEL REICHERT - UFPE
Externo à Instituição - ALEXANDRE TAVARES DA ROCHA
Externo à Instituição - MARCELO METRI CORREA - UFAPE