广东省惠来县土壤硒的分布特征及影响因素研究

目的]开展对广东省惠来县土壤硒的调查研究,系统采集了表层土壤组合样321个,深层母质土壤组合样79个,测定土壤全硒含量,并据此研究土壤硒分布特征及主要影响因素。方法]利用Pearson相关分析法与一元线性回归方法计算出土壤全硒含量与土壤理化性质和组分之间的相关性,GIS空间分析技术等方法对土壤硒的含量分布、富集特征及影响因素进行了系统的分析。结果]惠来县土壤总体属于富硒水平。硒含量变化于0.02～1.41mg/kg,平均值为0.50mg/kg,明显高于全国土壤硒平均值0.29mg/kg。表层土壤富硒面积为60.75%,足硒面积为28.35%;深层土壤中,富硒和足硒面积分别达到了72.15%和20.25%。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pH呈极显著负相关。结论]影响惠来县土壤硒含量的主要因素是成土母质,土壤pH、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。整体来看土壤硒含量水平较高,应针对富硒、足硒土地制定合理保护、开发和永续利用的方法与政策。

DISTRIBUTION OF SELENIUM AND ITS INFLUENCING FACTORS IN SOILS OF HUILAI COUNTY, GUANGDONG PROVINCE

A systematic investigation of soil selenium in the region of Huilai county, Guangdong province was carried out. A total of 321 surface soil samples and 79 deep soil samples were collected to determine the total selenium content in the soil, and the distribution characteristics and main influencing factors of soil selenium were studied accordingly. The correlation between soil total selenium content and soil physical and chemical properties and components was calculated by Pearson correlation analysis method and the unary linear regression method. The GIS spatial analysis technology and other methods were used to systematically analyze the distribution, enrichment characteristics and influencing factors of soil selenium content. Results showed that the soil in Huilai county was generally rich in selenium. The content of total selenium in the surface soils varied from 0.02 to 1.41mg/kg with a mean value of 0.50mg/kg, which was evidently higher than the national average selenium content of 0.40 mg/kg, the area of selenium abundance and selenium sufficiency in the surface soils was 60.75% and 28.35%, respectively. In the deep soils, the area of selenium abundance and selenium sufficiency reached 72.15% and 20.25%, respectively. Regression analysis showed that the total selenium content of the soil had a very significant positive correlation with the content of iron, aluminum and total organic carbon (SOC), and a very significant negative correlation with the pH value. Soil parent material is the major factor that influences selenium concentration and distribution in the soils in Huilai county, different land use modes, soil pH, SOC, iron and aluminum also play important roles. Overall, the soil selenium content in the study area is relatively high, and methods and policies for reasonable protection, development and sustainable use of selenium rich and sufficient selenium land should be formulated.