茶园土壤锌的形态分布及其影响因素

采集我国南方13个茶园土壤样品,采用硝酸-高氯酸混酸消化测定土壤锌的全量,以Tessier法对土壤锌进行形态分级,探讨了茶园土壤锌的形态分布及其与土壤锌全量和土壤理化性质的关系。茶园土壤锌的形态分布表明,13个茶园土壤的锌含量略有差异,但均低于茶园所在地区土壤锌的背景含量。比较13个茶园土壤各形态锌的平均含量,茶园土壤锌的形态分布规律为残渣态>有机结合态>交换态>铁锰氧化物结合态>碳酸盐结合态。茶园土壤锌的形态分布与土壤锌全量的关系表明,随茶园土壤锌全量的增加,残渣态锌含量显著增加,碳酸盐结合态锌和铁锰氧化物结合态锌随土壤锌全量增加的趋势不显著。茶园土壤锌的形态分布与土壤理化性质的关系表明,交换态锌含量与土壤pH呈显著负相关;有机结合态锌与土壤阳子交换量显著负相关;残渣态锌与粘粒含量和阳离子交换量均呈显著正相关,碳酸盐结合态锌和铁锰氧化物结合态锌与土壤理化性质没有显著的相关关系。

Distribution of Forms of Zinc and Its Affecting Factors in Tea Garden Soils

The content and fractionation of zinc in tea garden soils as well as the relationships between Zn fraction and total of Zn and soil properties were studied in the investigation by collecting soil samples from 13 tea gardens located in main tea areas of China.The difference of total zinc concentrations among tea garden soils was not little and all contents of the metal were lower than background level of located areas.According to the average concentrations of each fraction in all tea garden soils,the forms of Zn in the soils were in an increasing order of: residual>organic>exchangeable>Fe-Mn oxides>carbonate.Except residual,all the forms of zinc had not significantly correlation with the total zinc concentration present in the soils,although the carbonate and Fe-Mn oxides of Zn increased with the total amount of Zn but not obvious.The content of Zn in exchangeable fraction increased significantly with decreasing soil pH.The content of organic Zn obviously increased with the decreasing of CEC.The residual Zn increased significantly with clay content increasing and CEC decreasing,respectively.Other relationships between the forms of Zn and soil properties were little.