长江三角洲典型地区土壤有效铜和锌的时空变化及其影响因素研究

在2004年土壤调查数据的基础上,参照1982年土壤普查的资料,分析了张家港市土壤中有效铜和有效锌的时空变化趋势,并探讨了土壤性质、农业生产管理措施及环境污染等因素对它们的影响。研究结果表明:二十几年来,该地区土壤中有效铜和有效锌含量有了显著增加。在空间上,虽然土壤有效性铜和锌在水耕人为土高于北部的潮湿雏形土的格局没有改变,但在局部地区积聚的现象较为明显。这些时空变异的特征是由于二十多年来该地区农业生产管理措施的改变,工业发展等的外在因素,通过土壤性质发生改变(pH降低、有机质含量增加)而造成的。同时,工业、农业和城市活动带来的废弃物进入土壤中,也可导致土壤有效铜和锌含量增加。土壤有效铜和锌的时空演变,导致了研究区出现了铜过量的土壤,因此今后注意土壤铜过量对作物产生的危害。而土壤有效锌虽然有所增加,但大部分土壤仍处于较低或缺乏的状态,农业生产中应注意恰当施用锌肥,以提高作物产量,改善作物品质。

Spatio-temporal Variability and Its Affecting Factors of Soil Available Copper and Zinc in a Typical Area of Yangtze River Delta Region

Based on the Second National Soil Survey (1980) and the latest soil survey data (2004),the spatio-temporal variability of soil available Copper (Cu) and Zinc (Zn) in Zhangjiagang,an industrialized vs. rural area in Yangtze River Delta region. Factors affecting the variability,such as soil properties,agricultural management practices and environmental pollution were discussed. The results indicated that concentrations of soil available Cu and Zn had significantly increased during the past more than 20 years in this area. Spatially,although the distribution pattern of higher concentrations of soil available Cu and Zn in Anthrosols than those in Cambosols has not significantly changed during this period,the areas with high levels of soil available Cu and Zn were found in both of soils. This spatial and temporal variability was owing to the effects of the intrinsic factors such as a decrease of soil pH and an increase of soil organic matter on soil available Cu and Zn that was resulted from extrinsic factors such as changes of agricultural management practices and development of industry. At the same time,wastes with high levels of Cu and Zn from industrial,agricultural and municipal activities entering into soils could lead to increases of soil available Cu and Zn. As a result of the variability,soil available Cu had already been excessive level to crop growth,which should be paid great attention. Although soil available Zn increased,it was still deficient for crop growth in a certain amount area of soil. Zinc fertilizers would be appropriately applied to improve crop yield and quality.