Influence of commercial formulation on the sorption and leaching behaviour of propyzamide in soil

Abstract

Experiments compared sorption and leaching behaviour for the herbicide propyzamide when applied to two soils either as technical material or in the commercial formulation Kerb® Flo. Sorption was investigated in batch systems as well as using a centrifugation technique to investigate changes in pesticide concentration in soil pore water over incubation periods of up to 28days. Studies with small soil columns compared leaching of technical and formulated pesticide for irrigation events (6 pore volumes) 1, 7, 14, 21 and 28days after treatment. There were no differences in sorption of technical and formulated propyzamide when measured by batch systems. Sorption of technical material was significantly greater than that of formulated pesticide in sandy loam (p<0.05), but not in sandy silt loam when measured by centrifugation of soil incubated at field capacity. Partition coefficients measured by batch and centrifugation methods were similar after 1day and those measured by centrifugation increased by factors of 5.3 to 7.5 over the next 4weeks. The mass of propyzamide leached from soil columns ranged between 1.1±0.33% and 14.4±3.2% of the applied amount. For all time intervals and in both soils, the mass of propyzamide leached was significantly greater (two-sided t-tests, p<0.001) for the formulated product than for the technical material. Leached losses decreased consistently with time in the sandy loam soil (losses after 28days were 14-17% of those after 1day), but with less consistency in the sandy silt loam. There was a highly significant effect of formulation on the leaching of propyzamide through soil (two-way ANOVA, p<0.001) as well as highly significant effects of time and soil type (p<0.001). Results are consistent with modelling studies where leaching from commercial products in the field could only be simulated by reducing sorption coefficients relative to those measured with technical material in the laboratory.

Leaching and Releasing Characteristics and Regularities of Sb and As from Antimony Mining Waste Rocks

“…As the passage of leaching time, the release amount of Sb and As showed an increasing tendency as a whole, and the mining waste rock was seriously eroded due to the increasingly enhanced leaching scouring action, so the water and air could enter inside the mining waste rock, and react with and its internal antimony compounds and arsenic compounds, and the long-lasting oxidation to Sb and As salts in waste rocks by water would cause more Sb and As being released from the waste rock due to oxidation reduction by water and air, and then enter the leaching solution, thus making the accumulative release amount increase. Under the rainy conditions in the south, the increase of rainfall will inevitably result in the relatively easier release of Sb and As from the waste rocks into the surrounding soil and water environment, thereby causing environmental pollution [22,23].…”

Fate, uptake, and distribution of nanoencapsulated pesticides in soil–earthworm systems and implications for environmental risk assessment

“…Other studies have explored the effects of formulation on pesticide behavior. In studies with chlorsulfuron, coformulants reduced sorption (Foldenyi et al ); studies with propyzamide (Khan and Brown ) showed sorption to increase; and studies with triticonazole, cyprodinil, propetamphos, and fludioxinil showed sorption to increase (Beigel et al ; Beigel and Barriuso ; Garcia‐Ortega et al ; Pose‐Juan et al ). The impacts of coformulants therefore likely depend on the a.i.…”

Effect of tank-mixed adjuvant on the behavior of chlorantraniliprole and difenoconazole in soil

“…Moreover, a previous study showed that the relative leaching difference between commercial pesticide formulations and technical pesticide materials increased with the solubility of pesticides in water, for example, 1.4 for azoystrobin while the factor of was 4.3 for the more water-soluble triadimenol [ 13 ]. However, no differences were observed in the adsorption of technical and formulated propyzamide, but leached mass of formulated propyzamide was significantly greater than that of technical propyzamide [ 14 ]. In other cases, several surfactants increased pesticide desorption, and hence, pesticide mobility [ 31 ].…”