广东省高州石鼓地区土壤硒分布特征及影响因素

富硒土壤是一种稀缺的土壤资源,具有重要的农业经济价值。以每1 km 8~16个点的表层(0~20 cm)、10条剖面的深层(100~220 cm)土壤以及6件岩石样品数据对广东省高州市石鼓地区硒分布特征及影响因素进行研究。结果表明,石鼓地区表层土壤以高硒为主,高硒面积达59.06%,适量硒土壤面积占40.94%,没有硒缺乏和硒过剩区域。深层土壤在硒含量适量区随深度变化不大,而在高硒区域硒富集于浅表层约60 cm处。表层土壤高硒含量位于北西侧及中部第四系冲积平原区,其次为北东部、中部新近系盆地相含油含煤地层,在南部白垩系河湖相砂泥岩硒含量基本呈自然状态―弱富集特征。土壤硒含量与土壤p H之间的关系不大,而与成土母质和有机质含量有关,富有机质的细粒土壤更有利于硒的富集。

Distribution of Soil Selenium in the Shigu area of Guangdong Province and its Influencing Factors

Selenium ( Se ) is a kind of trace element in the soil, which has an important agriculture economic values. A Multi -Purpose Regional Geochemical Survey was performed in the Shigu area of Guangdong Province, collecting soil samples from the surface (0~20 cm) and deep section (100~220 cm) soil layers, 8 ~16 samples every 1 km2 and 3 ~6 samples every one section, respectively, for statistic analysis of distribution of soil selenium in the Shigu area of Guangdong Province and its affecting factors. Results of the analysis show that the content of soil selenium in surface soil of the plain is higher than the average of the country, and its distribution is characterized by a rising trend from northwest to central, and high values in northeast, as will as low values in southern Cretaceous lacustrine sand and shale area. About 59. 06% of the soil in area is high selenium, and 40. 94% of the soil is sufficient. However, there is no deficiency and excess selenium area. Correlation analysis shows that there is no significant correlation between pH and soil selenium content, while the fine parent material and organic matter tend to adsorb Se thus enriching soil Se.