Leaching of the herbicide Bromacil after application on railroads in the Netherlands

Leaching of fluridone, hexazinone and simazine in sandy soils in the Netherlands.

“…From half-life data for hexazinone (Rhodes, 1980; and from the amounts recovered (Eist), it can be concluded that degradation can be so slow that contamination of deeper layers with hexazinone is possible even after a spring application. The data presented here and in former publications for bromacil (Zandvoort et al, 1980) show that contamination of deep er soil layers may occur on sandy soils with a low content of organic matter. To pre vent leaching of herbicides it is recommended that applications be restricted to her bicides with a short to moderate persistence on sandy soils with a low content of organic matter in spring.…”

“…On sandy soils with a very low organic matter content, adsorption of herbicides might be too low to prevent leaching and subsequent contamination of ground water. This may be illustrated with results obtained by Zandvoort et al (1980), who found that in a sand bed of a railway track with a low content of organic matter, bromacil penetrated to depths around 100 cm.…”

“…Soil samples for residue analysis by bio-assays were collected as described by Zandvoort et al (1980).…”

Determination of bromacil in groundwater and in high organic matter soils

“…Also, Webber and Best (1972) reported that bromacil was more persistent in an acid soil compared to a neutral soil. In New Zealand bromacil is widely used for controlling weeds in asparagus (Asparagus officinalis) and is often applied to large areas on an annual basis. Sandy soils are usually chosen for asparagus crops and these have been reported as highly prone to leaching of bromacil with consequent groundwater contamination (Hebb and Wheeler, 1978;Zandvoort et al, 1980;Gómez de Barreda et al, 1991;Tucker, 1978). However most New Zealand soils are acid and have a high organic matter content (Burney et al, 1975; Wells and Luke, 1968).…”