方正县土壤硒的分布特征及其与土壤性质的关系

Distribution Characteristics of Selenium in Fangzheng County and Its Relationship with Soil Properties

方正县是黑龙江省水稻主产区,为研究方正县土壤全硒(Se)的含量、分布特征及其与土壤性质的关系,在哈尔滨市所属方正县境内采集127个0~20 cm耕层土壤样品,分析了方正县土壤全硒含量及其影响因素。结果表明,方正县土壤全硒含量变幅为0.030~0.496 mg kg-1,算术平均值为0.228 mg kg-1略低于全国土壤平均硒含量,总体上处于中等、边缘及缺乏水平。在不同类型土壤中,泥炭土硒含量相对较高(0.267 mg kg-1)而沼泽土硒含量相对较低(0.153 mg kg-1)。不同成土母质中,以坡积物为母质发育的土壤硒含量较高(0.276 mg kg-1)而以冲洪积物为母质发育的土壤硒含量较低(0.207 mg kg-1)。在土地利用方面,稻田土壤全硒含量略高于旱地土壤。相关分析表明:土壤有机碳(SOC)与土壤粒径分布(PSD)是影响研究区表土层土壤硒含量的主要因素。

Fangzheng County is a main production area of rice in Heilongjiang Province, which also serves as the producing counties of the enriched-Selenium(Se) rice. To evaluate the total Se level and distribution, investigate its relationship with soil properties, 127 soil samples were collected from the surface layer(0 ~ 20 cm) in the study area(Fangzheng County) with the determination of their total Se contents. The results showed that the total Se content ranged from 0.030 to 0.496 mg kg-1with arithmetic mean of 0.228 mg kg-1, which was lower than the national average.On the whole, the selenium level of agricultural soils belonged to medium, marginal or deficient. Among soil types,peat soil had a relatively high Se content(0.267 mg kg-1), while bog soil had a relatively low Se content(0.153 mg kg-1). Among soil parent materials, the highest content were recorded in slope sediments with an average Se content by0.276 mg kg-1, while Alluvial-pluvial material was the lowest with an average by 0.207 mg kg-1. In terms of land use,paddy soils had a higher Se content than upland soils. Correlation and regression analysis showed that soil total organic carbon(SOC) and soil particle size distribution(PSD) were the main factors, which affected soil selenium content.