立体休闲翻耕降低土壤中氟磺胺草醚残留污染的研究

根据"土壤立体休闲原理",通过现代化机械技术将氟磺胺草醚的残留土层与心土层进行位置转换,同时利用液相色谱结合生物测定的方法,系统研究不同耕作方法对氟磺胺草醚残留降解情况、土壤微生物变化和甜菜受害恢复情况的影响。结果表明,立体休闲翻耕处理对氟磺胺草醚残留的降解率明显好于常规翻耕处理,立体休闲翻耕后氟磺胺草醚的残留量降低了79%,而常规耕翻处理仅为46%;并且立体休闲翻耕处理对微生物的恢复效果好于常规翻耕处理,在0～10 cm土层中真菌、放线菌数目高于常规翻耕处理,10～20 cm和20～30 cm土层真菌数目均高于常规翻耕处理,各土层中细菌、真菌和放线菌总数恢复率分别可达到4%、29%和12%;生物测定结果表明,立体休闲翻耕提高了受药害甜菜的株高、出苗率、鲜重和叶绿素的恢复率,分别提高了12.89%、58.50%、72.29%和41.78%,效果好于常规耕翻处理。综上可以看出,与常规翻耕技术相比,立体休闲翻耕技术可更有效地降低土壤中氟磺胺草醚的残留量并减小氟磺胺草醚残留对土壤中微生物和敏感作物甜菜的影响。

Soil Layer Replacement Reduced Fomesafen Residue in Soil

Replacing surface with subsoil could enhance degradation of organic pollutants in soils. In this study, fomesafen degradation, microbial dynamics and sugar beet damages were investigated under different tillage methods using high performance liquid chromatography and biological assay. Residue of fomesafen in soil decreased by 79% under soil layer replacement, whereas by 46% under the conventional tillage. Compared with the conventional tillage, the number of fungi in 0 cm to 10 cm, 10 cm to 20 cm, and 20 cm to 30 cm soil layers and actinomycetes in 0 cm to 10 cm soil layer were greater under soil layer replacement. The recovery rates of soil bacteria, fungi and actinomycetes were 4%, 29% and 12%, respectively. In soil layer replacement treatment, the emergence rate, plant height, chlorophyll and fresh weight of sugar beet increased by 12.89%, 58.50%, 72.29% and 41.78%, respectively, compared with the conventional tillage. These results suggest that soil layer replacement could be an effective way to remediate soils contaminated with fomesafen.