| .基于不同终点测定土壤中Zn的毒性阈值及其田间验证[J].农业环境科学学报,2013,32(3):. |
| 基于不同终点测定土壤中Zn的毒性阈值及其田间验证 |
| Toxicity Thresholds（ECx）of Zn in Soils as Determined by Different Endpoints and Its Validations in Fields |
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| DOI：10.11654/jaes.2013.03.021 |
| 中文关键词: 锌 毒性阈值 预测模型 田间验证 |
| 英文关键词: zinc toxicity thresholds predictive models validation |
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| 摘要点击次数: 1952 |
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| 中文摘要: |
| 利用Log-logistic剂量-效应函数模型，在实验室条件下分别利用大麦根伸长、西红柿及小白菜生长毒性及基质诱导硝化毒性测试方法，测定了16种不同性质土壤中Zn的毒性阈值，在此基础上建立了基于土壤性质主控因子的Zn的毒性预测模型，同时选取湖南祁阳酸性土和浙江嘉兴中性土验证了田间条件下土壤中Zn毒性阈值。结果表明：田间条件下，湖南祁阳土壤中Zn对玉米不同生长指标的EC10范围为37~51 mg·kg-1，EC50为127~312 mg·kg-1，不同测试指标的敏感性顺序为苗期叶面积>秸秆生物量>苗期株高>籽粒产量；浙江嘉兴水稻土中Zn的毒性阈值EC10为213~332 mg·kg-1，EC50为682~922 mg·kg-1，不同测定指标间的敏感性顺序为孕穗期叶绿素含量>秸秆生物量>苗期株高>籽粒产量。土壤中Zn的毒性阈值田间验证结果表明，实验室条件下基于不同评价终点测定的土壤中Zn的毒性阈值与田间条件下的吻合性在不同土壤间存在一定差异，相比而言，实验室条件下对偏中性的浙江嘉兴水稻土中Zn的毒性阈值测定结果与田间验证结果更接近；基于实验室条件下不同测试指标所测定的土壤中Zn毒性阈值与土壤主控因子间的预测模型能较好预测浙江嘉兴水稻土中Zn的毒性阈值，田间条件下所测定的ECx（x=10，50）值均在模型预测值的两倍的预测区间内；而对于偏酸性的湖南祁阳土壤，预测模型则低估了土壤中Zn的生态风险。 |
| 英文摘要: |
| Sixteen soils were selected to obtain the toxicity thresholds of Zn in soils based on four different bioassay toxicity endpoints（i.e. the barley root elongation, tomato biomass and bok choy growth, potential nitrification rate（PNR）） by using Log-logistic dose-response models, and the predicted models of soil Zn toxicity thresholds were established in laboratory condition. In order to validate the toxicity thresholds of Zn determined in lab condition, two sites were selected for tests under field condition, i.e. the acid red soil located in Qiyang, Hunan province and the neutral paddy soil located in Jiaxing, Zhejiang province. The results indicated that the 10%（EC10）and half inhibition（EC50） concentration of toxicity thresholds of Zn in the acid red soil fall in the range of 37～51 mg·kg-1 and 127～312 mg·kg-1, respectively, as determined by different maize growth indexes, the sensitivity of the test endpoints follows order of：leaf area>straw dry weight >plant height>grain dry weight; however, the 10%（EC10） and half inhibition（EC50） concentration of toxicity thresholds of Zn in the paddy soil were 213～332 mg·kg-1 and 682～922 mg·kg-1, respectively, as determined by different rice growth indexes, the sequence of the sensitive of the test endpoints follows the order of：SPAD values>straw dry weight>plant height>grain dry weight. The field validation result showed the coincidences between the toxicity thresholds of Zn obtained in lab and field conditions varies in different tested soils, the closer EC10 and EC50 were observed in the paddy soil than those in the red soil. The predictive models of Zn toxicity thresholds established based on the lab test data can predict well the toxicity values of Zn to rice in paddy soil in field condition, e.g. the determined toxicity thresholds of Zn in the paddy soil in field condition fall in the two folds of the prediction interval, however, in terms of acid red soil, the predictive model underestimated the ecological risk of Zn in the soil. |
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