利用^(15)N示踪技术探讨烟株对氮素肥料的吸收与分配

Exploring Tobacco Plant′s Absorption and Distribution of Nitrogen Fertilizers by Using ^(15)N Tracing Technique

通过不同施肥方法的15N示踪技术研究得到:烟株各部位总氮含量以叶片>茎>根>顶杈,烟叶叶片总氮积累量为上部叶>中部叶>下部叶的规律。不同施肥方法的氮肥利用率、总氮含量以肥料1/3基施2/3追施处理较高,2/3基施1/3追施处理居中,全部条施处理较低。氮肥利用率以栽后100d左右较高。通过15N的原子百分超的测定结果得到烟株全氮中来源于吸收肥料氮的比例在不同部位的分布是随着叶位的升高而降低,来源于土壤氮的比例随着叶位的升高而增加。不同施肥方法的肥料氮比例以肥料1/3基施2/3追施处理较高,2/3基施1/3追施处理居中,全部条施处理较低。 N;吸收;分配;

The experiments were conducted through the 15N isotopic tracing of the different fertilizer application ways. The results showed that the total N contents in different parts of tobacco plant were arranged in order of leaf＞stem＞root＞bud and total N accumulation amounts in tobacco leaf were arranged in order of top leaf＞medium leaf＞bottom leaf. N fertilizer ultilization efficiency and total N content of different application ways were arranged in order of 1／3 base fertilizer +2/3 top dressing＞2/3 base fertilizer + 1/3 top dressing＞total row application. The highest N fertilizer ultilization efficiency was obtained at 100 days after transplanting. The 15N tracing determination results demonstrated that with the leaf position rised, the N absorption ratio from fertilizers was decreased, but that ratio from soil N sources was increased.