江西丰城生态硒谷土壤硒有效性及其影响因素

为了解丰城市生态硒谷土壤的供硒能力及其影响因素,通过实地调查采样,对丰城生态硒谷96个0~20 cm耕层土壤样品中硒含量、形态分布、重金属含量及部分土壤理化性质进行研究,并探讨与土壤硒有效性的关系。结果表明,该地区土壤全硒质量比变幅(541~831μg/kg)达到富硒土壤标准。易被生物利用的水溶态硒和可交换态硒质量比较少且在不同土壤样品中差异较大,变幅分别为10.30~38.23μg/kg和10.68~38.45μg/kg,且与土壤全硒有一定的相关性。土壤全硒、不同土地利用方式和土壤理化性质均对土壤硒的有效性产生影响,其中稻田土壤的供硒能力大于旱地,全P和速效P均与水溶态硒呈极显著正相关,在土壤硒有效性一定的条件下,全硒含量较高的土壤能够向作物提供较多的有效硒。

Effectiveness and influential factors of soil selenium in selenium valley,Fengcheng, Jiangxi

In this paper,we have investigated and analyzed 96 samples from Se-abundant soil collected from the ground-surface layer(0-20 cm) scattering in Fengcheng Ecological Selenium Valley through a series of experiments.The experiments we have done in the paper take it as a goal to identify and determine the impacts of the influential factors on the availability of selenium,aiming at doing more systematic studies on the availability of selenium in Se-abundant soils of the valley.To be exact,what we have done includes the following aspects,e.g.the heavy metal contents,the total selenium in the soil,the land-use situations,and the physical and chemical properties of the soil under study.The results of the said experiments verify that the aforementioned factors may have different effects on the availability of the soil selenium,for example,the total mass ratio of the soil selenium (541-831 μg/kg) in the region has been found so high as that equal to Se-rich soil national standard and the soil environment quality status-quo required by the human health in general.On the other hand,the water-soluble and exchangeable selenium with the high bioavailability should be kept in a low mass ratio range 10.30-38.23 μg/kg and 10.68-38.45 μg/kg,correspondingly.The two forms of selenium turn out to be distinct from each other soil sample.Meanwhile,they have also been proven to be correlated with the total selenium.The total selenium in soil,the different land uses and the physical and chemical properties of soil tend to have different impacts on the availability of the soil selenium.The activation coefficient of selenium in the paddy fields also proves higher than that in the dry land.What is more,the total phosphorus and available phosphorus contents prove also to be obviously in the positive correlation with the water-soluble selenium.Under certain conditions for the effectiveness of selenium,the soil which has higher total selenium content can provide more available selenium to the crop.Therefore,the research results of the paper can be expected to make more sense in the search into the availability and applicability of selenium so as to provide a theoretical basis for exploiting the selenium-rich soil resources in Fengcheng Ecological Selenium Valley.Hence,to some extent,our work is also helpful to promote self-protection of human health.