Sorção e mobilidade do ametryn em latossolos com diferentes características físicas e químicas

• Autor(a) principal: Silva, Luciano Lopes
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5437
• topic: Argila; Matéria orgânica; CTC; pH; Clay; Organic matter; CTC; pH; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO

The objective of this work was to evaluating the sorption and mobility of Ametryn in four types of soils [Red-Yellow Latosol (LVA), Humic Red-Yellow Latosol (LVAh), Red Latosol (LV) and Yellow Latasol (LA)], at different pH values. For such, samples of these soils were collected at the depth of 0-20 cm and characterized physically and chemically. Acid neutralization curves were generated for each soil. Shortly after, it was performed the correction of soil acidity (for LVA, LVAh and LV), at pH values close to 6,0. LA was evaluated only at pH 6,3. Before implanting the study on ametryn mobility, preliminary assays were carried out, one for each soil, aiming at determining the herbicide dose which inhibits by 50% the accumulation of dry matter by the aerial part of cucumber plants (Cucumis sativus), used as indicator species. Based on the data achieved, it was calculated the ametryn sorption ratio in the soils in relation to the inert substrate. The following sequence of sorption ratio in the soils was observed: LVAh sc > LVA sc > LVA cc > LVAh cc > LV sc > LA sc > LV cc (cc = with acidity correction; sc = without acidity correction). To evaluate ametryn mobility, PVC columns were used, with 10 cm of diameter and 50 cm of length. They were duly prepared and filled with the respective soils, and 4,0 kg ha-1 of ametryn were applied to the top of these columns. Twelve hours after herbicide application, a rain of 60 mm was simulated. After 72 hours, the columns were opened longitudinally andplaced in the horizontal position. The indicator species was sown along the columns for the assessment of ametryn mobility in the soils. The experiment was carried out in a completely randomized design, in split plot, with four replications. The experiment was composed of 70 treatments - seven substrates and ten segments (development of the indicator plants in the substrates of the columns at the depths of 0-5, 5-10, 10-15,15-20, 20-25, 25-30, 30-35, 35-40, 40-45 and 45-50 cm). Besides, a control without herbicide was used for each soil. It was concluded that the lowest ametryn mobilities occurred in soils with higher contents of clay and CTC, and that liming favored ametryn mobility in the soils investigated.