Processos de retenção, transporte e transformação em solos dos herbicidas diuron, hexazinone e sulfometuronmethyl

Detalhes bibliográficos
Ano de defesa: 2020
Autor(a) principal: Silva, Cydianne Cavalcante da
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal Rural do Semi-Árido
Brasil
Centro de Ciências Agrárias - CCA
UFERSA
Programa de Pós-Graduação em Manejo de Solo e Água
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: https://repositorio.ufersa.edu.br/handle/prefix/5898
Resumo: Knowledge on the processes involved among herbicides and soil is essential to define the application rates, maximizing the control of weeds and minimizing environmental risk caused by the residues of this pesticide. Several processes define the final destination of the herbicide, which can vary according to the physical and chemical characteristics of the soil. In this research, the sorption, desorption, leaching and half-life of the herbicides diuron, hexazinone and sulfometuron-methyl were evaluated in the following soils: Cambissolo Háplico, Latossolo Vermelho and Neossolo Quartzarênico. The sorption and desorption tests were estimated according to the “Batch Equilibrium”, method based on sorption and desorption isotherms. The leaching of herbicides was estimated in PVC columns at seven depths (0 to 0.35 m). The halflife was estimated in pots during times equivalent to 1, 3, 7, 15, 30, 45, 60, 120 and 180 days after application of the herbicide. The detection and quantification of herbicides in the samples of all experiments were analyzed by Ultra High-Performance Liquid Chromatography coupled to the Mass Spectrometer (LC-MS/MS). The sorption of the three herbicides was influenced by the pH and CTC of the studied soils, where the Latossolo showed greater sorption among the soils under the influence of the three herbicides applied. The highest sorption of the three herbicides in the Latossolo had a positive correlation in the half-life results (t1/2), except for hexazinone, whose t1/2 was higher in the Neossolo. Leaching for diuron remained in the upper layers of the soil, while hexazinone and sulfometuron-methyl leached to deeper layers. The GUS index indicated the highest risk of leaching for hexazinone compared to other herbicides in all soils. Hexazinone and sulfometuron-methyl can assist in the control of propagules in deeper layers of the soil, but their environmental risk of leaching must be considered when defining the dose used