硝化抑制剂对不同氮肥运筹下棉田土壤及棉株功能叶片氮素积累的影响

 通过在棉田中施用硝化抑制剂双氰胺（DCD）实现棉花增铵营养的途径，来改变传统棉田氮肥运筹途径和营养状况，同时考察了由此导致的棉田土壤和棉株功能叶片中氮素变化动态。结果表明：2％DCD的施用促进了棉株对氨基态氮的吸收而抑制棉株对硝态氮的吸收；同时也减少了棉田土壤中残留全氮含量、维持了土壤较高的氨基态氮含量，提高了氮肥吸收利用效率、节约了氮肥资源。进一步表明棉田中施用增铵营养在生理和生态上具有重要的意义。

Effects of Nitrogenous Fertilizer Strategies on the Nitrogen Accumulation in Cotton Field Soil and Cotton Functional leaves

Recent years, researchers have tried their best to control nitrogenous fertilizer loss and its pollution to environment. The mixed nitrogen nutrition becomes one of the new methods to enhance the effectiveness of nitrogen utilization and reduce the nitrogen loss. In the field conditions, enhanced ammonium nutrition (EAN) by using the nutrification inhibitor in soil becomes a very good ways to achieve the mixed nitrogen nutrition. Cotton is sensitive to nitrogen utilization. Meanwhile, due to growing in the hot season, the irrational nitrogenous fertilization utilization will lead to not only the poor cotton growth but also the larger nitrogen loss and environment pollution. With Bt-transgenic cotton 33B as experimental plant and Dicyanodiamide（DCD） as nitrification inhibitor, the effects of nitrogenous fertilizer strategies(including DCD and non-DCD treatment in different nitrogen levels) on the nitrogen accumulation in cotton field soil and cotton functional leaves were discussed. The results showed: 2% DCD treatment enhanced ammonium absorption（increased NH₄⁺ N from 0.70% to 112% in the main stem leaves and from 8.84% to 46.47% in the bearing stem leaves） and restrained nitrate absorption of cotton(decreased NO₃^{- _}N from 0.20%~22.68% in the main stem leaves and from 0.10% to 28.03% in the bearing stem leaves)，the extent of influence is different from one growth stage or nitrogen level from another; at the same time, it reduced the content of rudimental total nitrogen（decreased extent from 0 to 14.39%） and maintained the higher content of ammonium nitrogen（increased extent from 1.11% to 17.83%）in cotton and enhanced the efficiency of nitrogen fertilizer as well as saved nitrogen resource. These above mentioned further showed that it was important to treat cotton with EAN from the physiological and ecological perspectives.