贵州喀斯特地貌区三种类型耕地土壤性状分析——以贵阳市乌当区新场镇杨梅村为例

Soil properties of three types of farmland in karst area in Guizhou: A case study on Yangmei Village,Xinchang Town,Wudang District,Guiyang City

以贵阳市乌当区新场镇杨梅村为例,初步探究了贵州喀斯特地貌区坡耕地(SF)、缓坡旱地(GF)、水稻田(RF)中耕作层(TS)和底层(SS)土壤的5种理化性状和5种重金属含量。结果表明三种类型耕地的理化性状和重金属含量总体上均有明显差异。具体而言:1)pH变化范围为5.01~5.96,RF和SS土壤pH明显较高;2)有机质(SOM)和总氮(TN)含量表现为SF>RF>GF,总磷(TP)含量为GF>SF>RF,总钾(TK)含量则为RF>SF>GF,且SOM、TN和TP在三种耕地中均为TS>SS;3)5种重金属在两个土层几乎均呈现出RF>SF>GF的显著差异,且总体上均在TS层更高;三种耕地的As、Hg、Cr和Pb均属土壤质量第二级标准,而Cd则均超过了第二级标准值,是该村土壤的重金属超标指标。

Taking Yangmei Village,Xinchang Town, Wudang District, Guiyang City as the target area,we studied the 5 physicochemical properties and the content of 5 heavy metals in TS and SS soil of slope farmland （SF） , gentle slope farmland （GF） and rice field （RF）. The results showed significant differences among the three farmland types： （ 1 ） The soil pH ranged from 5. O1 to 5.96,and the pH value of RF and SS soil was obviously higher; （2） SOM and TN content ranked in the order of SF 〉 RF 〉 GF,TP content in the order of GF 〉 SF 〉 RF,TK content in the order of RF 〉 SF 〉 GF, and SOM, TN and TP content in TS soil was higher than that in SS soil ; （3） The content of the 5 heavy metals ranked in the order of RF 〉 SF 〉 GF, and their content in TS soil was higher than that in SS soil. As, Hg, Cr and Pb content was within the second level of the national standard, while Cd content exceeded the standard, becoming the main heavy metal pollutant of the target area.