Qiutong Xu, Mingkui Zhang
Institute of Soil and Water Resource and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058,China.
Institute of Soil and Water Resource and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058,China.
Ecotoxicol Environ Saf. 2017 Aug;142:410-416. doi: 10.1016/j.ecoenv.2017.03.035. Epub 2017 Apr 28.
Vegetable production in China is suffering increasingly heavy metal damages from various pollution sources including agricultural, industrial and other activities. It is of practical significance to understand the effects of human activities on the accumulation and exchangeability of soil heavy metals in vegetable fields. In this study, seventy-two arable layer samples of vegetable soils were collected from the Shaoxing coastal plain, a representative region of the coastal plain of eastern Zhejiang province, China for characterizing the effects of fertilization methods on accumulation and exchangeable heavy metals in soils (Exchangeable heavy metals in the soil samples were extracted by 0.01molL CaCl). The different origins of heavy metals in the vegetable soils were investigated by multivariate statistical techniques, including principal component analysis (PCA) and cluster analysis (CA). Marked increases were noted for soil heavy metals due to long-term manure or chemical fertilizer application. Three significant components were extracted by PCA, explaining 78.86% of total variance. Mn, Co, Ni, Fe, and Al were associated in lithogenic components, while an anthropogenic origin was identified for Cu, Cr, Pb, Zn, Cd, Hg. However, As level was due to the geochemical background and was not linked to soil management. The results obtained by cluster analysis elucidated individual relationships between metals and agreed with PCA. Cu, Cr, Pb, and Zn in the soils that were mainly associated with the application of chemical fertilizers, organic manures or other activities regarding soil management. Although the origin of Cd, Hg, and As was also attributed to soil management, other sources like vehicle exhaust or aerial depositions were not discarded as possible contributors. Soil amended with organic fertilizer contained more Cu, Pb, Zn and Cr; whereas the soil amended with chemical fertilizer had more Cd. Application of fertilizers also had significant effect on the concentrations of exchangeable heavy metals. Higher mean concentrations of exchangeable Cd and Pb were found in the soils amended with chemical fertilizers, while those of exchangeable Cu and Zn were found in the soils amended with organic fertilizers.
中国蔬菜生产正遭受来自包括农业、工业及其他活动在内的各种污染源日益严重的重金属损害。了解人类活动对菜地土壤重金属积累和交换性的影响具有实际意义。本研究从中国浙江省东部沿海平原的典型区域绍兴沿海平原采集了72个菜地耕层土壤样本，以表征施肥方式对土壤中重金属积累和交换性的影响（土壤样本中的交换性重金属通过0.01mol/L CaCl₂提取）。采用主成分分析（PCA）和聚类分析（CA）等多元统计技术研究了菜地土壤中重金属的不同来源。长期施用粪肥或化肥导致土壤重金属显著增加。通过主成分分析提取了三个显著成分，解释了总方差的78.86%。锰、钴、镍、铁和铝与成岩成分相关，而铜、铬、铅、锌、镉、汞则被确定为人为来源。然而，砷含量归因于地球化学背景，与土壤管理无关。聚类分析结果阐明了金属之间的个体关系，与主成分分析结果一致。土壤中的铜、铬、铅和锌主要与化肥施用、有机肥料或其他土壤管理活动有关。虽然镉、汞和砷的来源也归因于土壤管理，但车辆尾气或大气沉降等其他来源也可能是其贡献因素。施用有机肥的土壤含有更多的铜、铅、锌和铬；而施用化肥的土壤镉含量更高。施肥对交换性重金属浓度也有显著影响。施用化肥的土壤中交换性镉和铅的平均浓度较高，而施用有机肥的土壤中交换性铜和锌的平均浓度较高。
