广东省普宁市土壤硒的分布特征及影响因素研究

开展了广东省普宁市区域土壤硒调查研究,采集了413个表层土壤样品(0～20 cm)和103个深层土壤样品(> 150 cm),测定了土壤全硒含量,据此研究土壤硒分布特征及其影响因素。结果表明,普宁市土壤全硒含量变化于0. 16～2. 01 mg/kg,平均值为0. 63 mg/kg,总体上处于中硒及高硒水平,不存在缺硒和硒过剩土壤。砂页岩风化形成的赤红壤全硒含量较高,平均值达0. 86 mg/kg,以侏罗系页岩母质发育的土壤全硒含量最高,平均值达0. 89 mg/kg;三角洲第四系沉积物发育形成的水稻土全硒含量最低,平均值为0. 41 mg/kg。回归分析表明,土壤全硒含量与铁铝含量、有机碳含量具有极显著正相关,与p H呈极显著负相关。影响普宁市土壤硒含量的主要因素是成土母质,土壤p H、有机碳和铁铝含量及土地利用方式对土壤全硒含量分布与富集也有一定的影响。

Distribution of Selenium and Its Influencing Factors in Soils of Puning City,Guangdong Province

A systematic investigation of soil selenium in the region of Puning City was carried out, and 413 samples of surface soil (0-20 cm) and 103 samples of deep soil (>150 cm) were collected systematically and analyzed for content, distribution and influencing factors of soil Se. Results showed that the content of total selenium in the surface soils ranged from 0.16 mg/kg to 2.01 mg/kg with a mean value of 0.63 mg/kg, which meant that the soils were in the category of Se sufficiency or Se abundance on the whole, with none in the category of Se deficiency or excessive Se. Among the different types of soils, total Se content was the highest in red soil formed by sand shale, averaging 0.86 mg/kg,and the lowest in paddy soils developed in delta sediments, averaging 0.41 mg/kg. Among the different types of parent materials, the highest content was recorded in Jurassic shale with an average Se content of 0.89 mg/kg, while the lowest in Quaternary sediment with an average of 0.41 mg/kg. Correlation and regression analysis showed that soil Se content was significantly and positively related to contents of iron and aluminum, soil total organic carbon (SOC), but negatively to soil pH. Soil parent material was the major factor influencing selenium concentration and distribution in the soil of Puning City, whereas land use, soil pH, SOC, iron and aluminum also played important roles.