James Trevor K, Ghanizadeh Hossein, Harrington Kerry C, Bolan Nanthi S
a AgResearch, Ruakura Research Centre , Hamilton , New Zealand.
b School of Agriculture and Environment , Massey University , Palmerston North , New Zealand.
J Environ Sci Health B. 2019;54(5):407-415. doi: 10.1080/03601234.2019.1574170. Epub 2019 Feb 7.
Organic soil amendments can be useful for improving degraded soil, but this increase in organic matter (OM) may influence adsorption of herbicides subsequently applied to the treated soil, even though the particle size of amendments and their nature differ from typical soil OM. In this study, a batch equilibrium method was used to measure adsorption of five herbicides following application to two organic media, wood pulp and sawdust, comparing these with two cropping soils. Herbicide adsorption, quantified by distribution coefficients (k), was much higher in the two organic media than in the cropping soils. The increases in adsorption were strongly correlated to the percentage of organic carbon. When the k was normalized to adsorption coefficients corrected for OM content (k), variation in results between the media was greatly reduced, indicating that OM is an important factor influencing adsorption in these media. The results of this study suggest that herbicides will be less effective when applied to soils in which sawdust and wood pulp have been added. Using organic amendments to remediate soil will increase adsorption of pesticides, reducing their bio-availability and efficacy, but also reducing their tendency to leach into root zones of deep-rooted crops and into groundwater.
有机土壤改良剂有助于改善退化土壤，但有机质（OM）的增加可能会影响后续施用于处理过的土壤中的除草剂的吸附，尽管改良剂的粒径及其性质与典型的土壤有机质不同。在本研究中，采用批量平衡法测定了五种除草剂施用于两种有机介质（木浆和锯末）后的吸附情况，并将其与两种种植土壤进行比较。通过分配系数（k）量化的除草剂吸附在两种有机介质中比在种植土壤中高得多。吸附的增加与有机碳的百分比密切相关。当k被归一化为针对OM含量校正的吸附系数（k）时，介质之间结果的差异大大降低，表明OM是影响这些介质中吸附的重要因素。本研究结果表明，将除草剂施用于添加了锯末和木浆的土壤时效果会较差。使用有机改良剂修复土壤会增加农药的吸附，降低其生物有效性和功效，但也会降低其渗入深根作物根区和地下水的趋势。
