不同调控措施对减量施肥条件下油菜硝酸盐含量及氮素利用率的影响

利用室内盆栽试验,研究了较低肥力菜田土壤上不同施肥量及减量施肥配合不同氮素调控剂处理对油菜生长、硝酸盐含量以及土壤硝态氮含量和氮肥利用率变化的影响。结果表明：无论是根施调控剂还是不同叶面调控剂处理都有效提高了油菜的生物学产量;根施双氰胺复合硝化抑制调控剂（根调）以及叶面喷施调控剂1和调控剂2处理显著降低了油菜硝酸盐含量,降幅分别达到62.8%、70.3%和73.4%;根调和叶面喷施肥＋扩展剂调控处理也有效地降低了土壤硝态氮含量,提高了氮肥利用率,根调以及叶面调控剂处理下氮肥利用率大幅提高,尤其是根调处理下最高达到61.0%,氮素表观损失量降低,根调处理下最高达68.4%。以上结果说明,较低肥力菜田土壤适量施肥条件下,氮素调控剂如双氰胺复合硝化抑制调控剂的合理施用在保证蔬菜产量基础上,不仅有利于降低蔬菜硝酸盐含量,而且有利于提高氮素利用率,减少肥料氮素环境损失量。

Influences of Different Regulation Measures on Nitrate Content and Nitrogen Use Efficiency in Rape under the Conditions of Nitrogen Reduction Application

Indoor pot experiment on the effects of different fertilizer doses treatments and nitrogen reduction application combined with nitrogen regulating agents on rape growth,nitrate content in plant and in soils,and nitrogen use efficiency were conducted.The results showed that regulating agents applied both in roots and on leaves improved effectively the yield of rapeseed;the treatments of dicyandiamide nitrification inhibiting compound agents applied in roots（root regulation）and foliar spray regulating agent 1 and 2 reduced significantly the nitrate content in rapeseed,with a decline of 62.8%,70.3% and 73.4% respectively;the root regulation and the foliar spray fertilizer combined with spreading agent also reduced obviously the soil nitrate content,and improved the nitrogen use efficiency（up to 61.0% by root regulation）,and reduced the apparent loss of nitrogen（up to 68.4% by root regulation）.The results suggested that under the conditions of appropriate amount fertilizer application to the vegetable soil with lower fertility,the rational application of the nitrogen-regulating agents such as dicyandiamide nitrification inhibiting compound,could not only help to reduce the nitrate content in vegetables,but also be conducive to improve nitrogen use efficiency,reduce nitrogen loss and ensure the production of vegetables.