广西桂中南部地区富硒土壤硒含量及其与土壤理化性状的关系

Selenium Contents and Their Relationship with Main Soil Properties in Farmland Soils of Southern Guizhong, Guanxi

为了解广西桂中南部地区富硒土壤的硒含量及其分布特征,明确土壤硒与主要土壤性状指标的关系,选择水田和旱田,分别于0~20 cm和150~200 cm深度取样,测定土壤全硒含量及主要理化性状。结果表明,桂中南部地区农田表层土壤(0~20 cm)全硒平均含量(算术平均值)为0.77 p.g g-',93.76%的农田表层土壤属于富硒土壤(0.4~3 p.g g"),深层土壤(150~200 cm)全硒平均含量为0.62 jig g=79.04%的深层土壤属于富硒土壤,研究区内的表层和深层土壤全硒都达到足硒标准(0.175~3.000|xg g-')o广西桂中南部研究区内农田土壤硒含量与土壤的Al2O3,Fe2O3,有机碳呈正相关,与pH值呈负相关,旱地土壤相对于水田土壤富Al2O3.Fe2O3>有机质,低pH值,导致旱地土壤的硒含量高于水田土壤。据此表明,广西桂中南部地区农田土壤有利于种植富硒作物。

The objectives of this study were to identify the characteristics of selenium(Se)content and distribution and to examine the relationship between Se content and main soil properties in the Se-enriched soil of southern Guizhong,Guangxi.The Se content and distribution and its relationship with the soil physio-chemical properties were analyzed at different soil depths(0一20 cm and 150-200 cm)under different land-use patterns(paddy and dry land).The results showed that the average content of Se was 0.77 jig g-1 in 0-20 cm surface soil and was 0.62|xg g_1 in 150-200 cm deep soil of the southern Guizhong.The Se contents were 0.4|xg g_I to 3.0|xg g_,in 93.76%surface soil and 79.04%deep soil.The Se content in farmland soil was positively correlated with A12O3,Fe2O3 and organic carbon,but negatively correlated with pH value.Compared with paddy soil,dryland soil was characterized with richer contents of A12O3,Fe2O3 and organic carbon and lower pH value,which resulted in higher Se content in dryland soil than that in paddy soil.The farmland soil is beneficial to the cultivation of Se-rich crops in the southern Guizhong,Guangxi.