Degradation rates of alachlor, atrazine and bentazone in the profiles of Polish Luvisols
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| Authors: | T. Paszko1, P. Muszyński1 1Department of Chemistry, University of Life Sciences in Lublin, Akademicka 13, 20-950 Lublin, Poland |
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| Abstract : | The degradation rates of three herbicides (alachlor, atrazine, and bentazone) were examined according to OECD Guideline 307 in three profiles of grey-brown podzolic soil (Luvisol) in a laboratory experiment. The aim of the experiment was to determine herbicide degradation parameters and their relationships with soil properties. Degradation processes were effectively described by a first-order model. However, in some cases, the best results were produced by bi-phasic kinetics (hockey-stick and bi-exponential model). The degradation rates of the tested herbicides at 25°C and 40% maximum water holding capacity, established based on half-life values in the Ap horizon, increased in the following order: atrazine (32.6-42.8 days) < bentazone (3.4-16.6 days < alachlor (4.4-5.7 days). The correlation analysis and the Principal Component Analysis revealed significant positive correlations between the herbicide degradation rates and the organic matter content of soils. The depth-dependent degradation factors obtained for topsoil and two subsoil horizons (1: 0.42: 0.11 – based on average values, and 1: 0.31: 0.12 – based on median values) reflect the degradation abilities of Polish Luvisols. The values noted are soil-specific; therefore, they can also be applied to other pesticides in Polish Luvisols. |
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| Keywords : | herbicide, degradation, soil horizons, depth-dependent degradation factor | ||||||||||
| Language : | English | ||||||||||