Plant Soil Environ., 2004, 50(8):333-338 | DOI: 10.17221/4040-PSE
Field and numerical study of chlorotoluron transport in the soil profile
- Czech University of Agriculture in Prague, Czech Republic
The transport of chlorotoluron in the soil profile under field conditions was studied. The herbicide Syncuran was applied on a four square meter plot using an application rate of 2.5 kg/ha active ingredient. Soil samples were taken after 119 days to study the residual chlorotoluron distribution in the soil profile. HYDRUS-1D (Šimůnek et al. 1998) was used to simulate water movement and herbicide transport in the soil profile. Soil hydraulic properties and their variability were studied previously by Kutílek et al. (1989). The solute transport parameters, like the adsorption isotherm and the degradation rate, were determined in the laboratory. The Freundlich and Langmuir equations were used to fit the experimental data points of the adsorption isotherm, and the affect of each type of adsorption isotherm equation on the solute transport was studied. The chlorotoluron concentrations in soil water tended to be higher for the simulation performed with the Freundlich isotherm then that of the model using the Langmuir isotherm. In both cases, the solution did not pass a depth of8 cm. The simulated chlorotoluron concentrations in soil samples were higher then the observed concentrations when the chlorotoluron degradation was assumed to be in soil water only. Assumption of the solute degradation in both in the solid and the liquid phase significantly improved the accuracy of the solution. The different characters of the simulated and observed chlorotoluron distributions can probably be attributed to the preferential flow of water and solute in the soil profile and by variability of the transport parameters.
Keywords: herbicide; chlorotoluron; adsorption isotherm; degradation rate; solution transport; field and numerical studies
Published: August 31, 2004 Show citation
References
- Kodeš V. (2003): Occurrence of dangerous substances in groundwater of the Czech Republic. Acta Hydrol. Slov., 4: 183-189. (In Czech)
- Kozák J., Vacek O. (2000): Pedotransfer functions as a tool for estimation of pesticides behavior in soils. Rostl. Výr., 46: 69-76.
- Kutílek M. et al. (1989): Structural assessment of the experimental field Tišice, Czech Republic, Department of Irrigation and Drainage. CTU, Prague.
- Šantrůček J., Svobodová M. (1992): The effects of plant damage and soil compaction in wheel traffic of harvesting machinery on yield capacity of lucerne. Rostl. Výr., 38: 357-364. (In Czech)
- Šimůnek J., Šejna M., van Genuchten M.Th. (1998): The HYDRUS-1D software package for simulating the one-dimensional movement of water, heat and multiple solutes in variably-saturated media. Version 2.0. IGWMC-TPS-53. International Ground Water Modeling Center, Colorado, School of Mines, Golden, CO.
- Šimůnek J., Šejna M., van Genuchten M. Th. (1999): The HYDRUS-2D software package for simulating the two-dimensional movement of water, heat and multiple solutes in variably-saturated media. Version 2.0. IGWMC-TPS-56. International Ground Water Modeling Center, Colorado, School of Mines, Golden, CO.
- USDA. Beltsville Area, Agricultural Research Service. The ARS Pesticide Properties Database: http://www.arsusda.gov/acsl/ppdb.html
- van Genuchten M.Th. (1980): A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci. Soc. Am. J., 44: 892-898.
Go to original source... - Wauchope R.D., Buttler T.M., Hornsby A.G., AugustijnBeckers P.W.M., Burt J.P. (1992): The SCS/ARS/CES pesticides database for environmental decision making. In: George W.W. (ed.): Review of environmental contamination and toxicology. Vol. 123. SpringerVerlag. Go to original source...
This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY NC 4.0), which permits non-comercial use, distribution, and reproduction in any medium, provided the original publication is properly cited. No use, distribution or reproduction is permitted which does not comply with these terms.