李福燕 李许明

摘要 采集海口市23个乡镇和4个农场的751个农用地土壤耕作层（0～25 cm）样品，研究分析了土壤有机质含量、pH、全氮、全磷、全钾和全硒含量，并对土壤中全硒含量和土壤理化性质相关性进行了分析。结果表明：海口市农用地土壤有机质含量总体上处于中上水平，全省有机质平均含量为 27.79 g/kg，各地区之间含量差异较大，最大值为最小值的29.22倍;土壤 pH 平均为5.40，为酸性土壤;土壤全氮平均含量为1.72 g/kg，大部分地区氮含量属于中等偏上水平;土壤全磷含量的平均值为0.94 g/kg，磷含量地区间差异较大;土壤全钾平均含量为2.06 g/kg，全市土壤钾含量偏低，88%以上土壤处于中下水平;所调查土壤硒含量从痕量到2.23 mg/kg，平均值为0.35 mg/kg，明显高于全省平均值0.211 mg/kg，45.54%的土壤硒含量处于中等及以上水平（0.175 mg/kg），其中29.29%属于高硒含量，但各个乡镇硒含量差异较大。从相关性分析可知，土壤硒含量与pH、全磷和全钾呈极显著或显著正相关，与有机质和全氮呈负相关，表明土壤中硒主要来源于土壤母质。

关键词 海口;硒;理化性质;含量;相关性

中图分类号 S153 文献标识码 A 文章编号 0517-6611（2020）14-0042-06

doi：10.3969/j.issn.0517-6611.2020.14.013

Abstract Total of 751 samples were collected from the arable land（0-20 cm）in the 23 towns and 4 farmlands of Haikou City，soil organic matter（SOM），pH，total nitrogen（TN），total phosphorus（TP），total potassium（TK）and Se contents of those samples were analyzed.Then the correlations between Se content and soil physicochemical properties were established.The result showed that all of the soil samples from the arable land were acidic，with a pH value of 5.40.The SOM content of the arable land in Haikou City was above average level，the mean value of which was 27.79 g/kg，a relatively large range was showed in different regions，the ratio between the maximum and minimum value could be up to 29.22.The mean value of TN content was 1.72 g/kg，most samples were above average level.The TP content had a large variance，with a mean value of 0.94 g/kg.The mean TK content was 2.06 g/kg，88% of which were in the low level.The Se content ranging from trace amounts to 2.23 mg/kg，and the mean value was 0.35 mg/kg，which was significantly higher than the average value （0.211 mg/kg）of total province.About 45.54% of the total samples were higher than 0.175 mg/kg，and 29.29% of which were enriched with Se.However，the variability was great between the towns.The correlation analysis indicated that the Se content had significant and positive relation with the pH，TP and TK，and the negative correlation was existed between Se content and SOM and TN content，which suggested that the Se was mainly come from the parent material.

Key words Haikou;Selenium;Physicochemical properties;Content;Correlation

硒是環境中极重要的生命元素，是人体必需的14种微量元素之一[1]，研究表明硒过量或缺乏都会导致人体产生多种病症[2-4]。硒在岩石、土壤中分布极不均匀，自然土壤中的硒主要来自于母岩，岩石中的硒通过风化作用进入土壤。因土壤母质和气候条件的差异，不同地区土壤中硒含量差异很大。从世界范围来看，土壤硒缺乏很普遍，我国是世界上严重缺硒国家之一，有70%以上的地区缺硒[5]。……