Residues and transportation of atrazine herbicide in maize (Zea mays L.) cultivated upland soil, soil sediment and stream water in Huay Kapo watershed, Nam Nao district, Phetchabun province
2011
On-Anong Phewnil(Kasetsart University, Bangkok (Thailand). College of Environment) E-mail:[email protected] | Supamard Panichsakpatana(Kasetsart University, Bangkok (Thailand). Faculty of Agriculture. Department of Soil Science) | Nipon Tungkananuruk(Kasetsart University, Bangkok (Thailand). College of Environment) | Bongotrat Pitiyont(Kasetsart University, Bangkok (Thailand). Faculty of Science. Department of Environmental Science) | Namyen Siripat(Department of Agriculture, Bangkok (Thailand). Office of Agriculture)
Huay Kapo Watershed is located in Lak Dan Sub-District, Nam Nao District, Phetchabun Province, Thailand. The watershed is located at approximately 400-920 m MSL, has high erodibility, and a high soil loss rate (19.224 ton/rai/yr). This area is used to cultivate maize (Zea mays L.) year round and receives atrazine at the rate between 200-250 g/rai. Top soil (0-15 cm.) at the amount of 80 percent of the total 48 samples contained atrazine, with the 133.59 micro g/kg average concentration, while 83.33 percent of the total 50 samples of subsoil (15-30 cm.) was contaminated with atrazine at the average concentration of 183.23 micro g/kg. Furthermore, 71.76 percent of the sediment samples were found to contain atrazine at the average concentration of 27.42 micro g/kg. Stream water samples at the amount of 63.33 percent of all samples were contaminated with atrazine from the cultivated area with the average concentration of 4.7 micro g/L. The stream water as many as 15 samples (39.47 percent of the total samples) contained atrazine in levels higher than the standard limit of atrazine concentration in drinking water set by USEPA at 3 micro g/L. Atrazine in the upland soil was 4.87-fold higher than that in the soil sediment and 39-fold higher than that in the stream water. Additionally, the content of atrazine in the soil sediment was 5.87-fold higher than that in the stream water. The results revealed that atrazine was transported from upland soils into the aquatic environment by adsorption, run-off and leaching processes.
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