设施栽培条件下蔬菜含硒状况及其健康风险评估

设施栽培条件下土壤性质变化剧烈,其对作物吸收硒(Se)的影响值得研究。本文通过对南京市典型设施蔬菜种植基地土壤及对应植物样品进行取样分析,探讨高强度利用模式下土壤Se的存在形态以及不同蔬菜类型对Se吸收的差异,分析蔬菜Se含量与土壤Se存在形态及土壤性质之间的关系,并对长期设施栽培条件下蔬菜Se的摄入健康风险进行评价。结果表明,不同蔬菜可食部分对Se的富集能力表现为叶菜类(平均含Se量为60μg/kg,干重)根茎类(30μg/kg)茄果类(26μg/kg)。蔬菜可食部分Se含量随土壤有机质及有机结合态Se含量的增加而降低。研究区域有机肥的大量施入引起的有机结合态Se含量的增加可能是降低Se有效性的最重要原因。

Effect of Greenhouse Vegetable Cultivation Under Intensive Utilized Conditions on Selenium Content in Vegetables

Little information is available on the effects of intensive greenhouse cultivation on selenium (Se) content in vegetables. This study was conducted in a typical greenhouse vegetable cultivation field in Nanjing. Soil samples as well as corresponding vegetables were collected, and Se contents were analyzed to reveal the factors affecting vegetable Se content. The health risk of Se intake through vegetables was also evaluated. The results showed that the contents of Se in vegetables varied with vegetable species and followed the order: leafy vegetable > tuber vegetable > fruit vegetable. Vegetable Se content decreased with increased soil organic matter (OM) content and organic bound Se content. This might be due to the large amounts of organic fertilizer input, which increased soil OM content as well as organic bound Se content, and thus decreased soil Se availability. The background soil Se level in study area was low. The decrease in vegetable Se content induced by application of organic fertilizer increased the health risk of Se deficiency to human.