基于回归方程的硒元素生物有效性研究

Bioavailability of Selenium Based on Regression Equation

在重庆市南川区采集表层土壤样8946件、主要农作物水稻155件,另采集马铃薯、番茄、玉米、黄瓜、茄子和豇豆样品(农作物样配套采集根系土样品)。以元素富集系数表征元素生物有效性,通过回归方程研究其影响因素。结果显示水稻富硒率为49.03%,土壤硒元素含量等级二等面积为40.2%,具备开发富硒农产品的潜力。回归方程显示,Se生物有效性受到土壤中S、P含量及土壤pH的共同影响,土壤碱性条件下,Se生物有效性更高,土壤S与硒表现为拮抗作用,土壤P能促进植物对硒的吸收。水稻硒含量预测结果显示,研究区水稻达到富硒水平的比例为56.1%,适宜大规模生产富硒水稻。对比研究区不同种类农作物对硒的富集程度发现,豇豆及水稻对硒的富集能力较强,为建议种植农作物。可通过人为手段调控田块土壤理化性质、适当增加磷肥施用量及调整田块种植结构的方法,提高土壤Se的利用率。

A total of 8946 surface soil samples and 155 rice samples were collected from Nanchuan District,Chongqing.Plant samples of corn,potato,tomato,cucumber,eggplant and cowpea samples were collected for testing and analysis(collect corresponding rhizosphere soil samples).Element bio-availability was characterized by element enrichment coefficient,and its influencing factors were studied by using the regression equation.The results showed that the selenium(Se)enrichment percentage of rice was 49.03%.About 40.2%of the soil in the study area was at the second grade of Se content,which had the potential to develop Se-rich agricultural products.The Se bioavailability was affected by the contents of soil sulfur(S)and phosphorus and the value of soil pH.Under alkaline conditions,Se bioavailability was higher.Soil sulfur and Se act as antagonistic effects.Soil P promoted the absorption of Se by plants.The prediction results of rice Se content showed that 56.1%of rice in the study area reached at the Se-rich level,which was suitable for large-scale production of Se-rich rice.Compared with the other crops enriching Se in the study area,cowpea and rice had the strong Se enrichment ability,which were recommended to grow.The artificial means could be used to adjust soil physical and chemical properties,appropriately increase the applying amount of phosphate fertilizer,and adjust the planting structure in order to improve the utilization efficiency of soil Se.