黑土土壤硝态氮时空变异对蔬菜硝酸盐含量的影响

在等氮量的条件下,研究了黑土土壤硝态氮、铵态氮的时空变异和不同形态氮对大白菜硝酸盐含量的影响。试验结果表明,不同形态的氮素肥料其溶解度不同,淋洗的数量和形式也不一样,其向下移动的快慢的顺序是硝酸钙>尿素>硫酸铵>有机肥;肥料种类也是影响硝酸盐含量的重要因素,其顺序是尿素>硝酸钙>有机肥>硫酸铵。在成熟期,施用硫酸铵符合国家蔬菜硝酸盐含量一级标准,施用有机肥符合国家蔬菜硝酸盐含量二级标准,施用尿素和硝酸钙符合国家蔬菜硝酸盐含量四级标准。由此可见,大白菜硝酸盐含量超标十分严重,了解大白菜硝酸盐积累规律和变化动向,采取有效措施控制大白菜中的硝酸盐含量,对发展无公害蔬菜生产和提高人民生活质量与健康的水平有着重要的意义。

Influence of Nitrate-N Space Time Differentiation to Ch. Cabbage Nitrate Content in Black Soil

In the condition of the equal weight N input, we researched the influence of nitrate-N space time differentiation and different type of N to Ch. cabbage nitrate content. Our conclusion is that the solubility is different among N fertilizer, also the quantity and form of moving is different. The sequence of moving down speed is nitrate-ca>urea>Sulphuric-NH4>organic fertilizer. The type of N fertilizer is important to Ch. cabbage nitrate content. The sequence is urea>Nitrate-Ca>organic fertilizer>Sulphuric-NH4. The Chcabbage accord to the national first order standard about nitrate content if we use Sulphuric-NH4 in the ripe times. It accords to the national second order standard about nitrate content if we use organic fertilizer in the ripe times. It accords to the national second order standard about nitrate content if we use urea or Nitrate-Ca. So Ch. cabbage nitrate content exceeded quota very serious. To know the nitrate roll up and change regular and how to control the nitrate content are very important to develop no social effects of pollution agriculture and improve people is life level.