施氮深度对‘黄金梨’树氮素吸收、分配及利用效率的影响

The Influences of Different Fertilization Depth on the Nitrogen Absorption,Distribution and Utilization of ‘Hwangkumbae’ Pear Trees

以7年生‘黄金梨’树为试材,采用^(15)N示踪技术研究了3个施氮深度[0(表面施氮)、20和40 cm]处理下不同器官对氮素的吸收、分配及利用效率,并探讨了氮素在土壤中的残留及损失。结果表明,梨果实成熟期,果实的Ndff值最高,其他器官的Ndff值均表现为20 cm施氮深度处理显著高于其他处理。各施氮深度处理,^(15)N的分配率均为贮藏器官最高,生殖器官最低。20 cm施氮深度处理的梨树N利用率最高(26.23%),40 cm施氮深度处理最低(15.65%)。N损失率以表面施氮处理最高(54.21%),20 cm施氮深度最低;0~80 cm土层的N残留率以40 cm施氮深度处理最高(31.73%),表面施氮处理最低。因此,本研究中,20 cm深度施氮处理能提高梨树各器官对N肥的吸收征调能力,氮素损失少。

In this field experiment,seven-year-old pear trees（Pyrus pyrifolia‘Hwangkumbae＇）were treated by ^（15） N-tracer to research the effects of fertilization depth（0,20 and 40 cm）on nitrogen absorption,distribution and utilization of different pear trees organs,residual and loss in the soil. The results indicate that the ^（15） N derived from fertilizer（Ndff）was the highest in the fruit at fruit maturity stage,and the Ndff in other organs of 20 cm treatment is significant higher than that of other treatments. The ^（15） N distribution ratio of each treatment is highest in storage organs and lowest in vegetative organs. The N utilization ration of 20 cm depth treatment is highest（26.23%）,and that of 40 cm depth treatment is lowest（15.65）;the N loss ration of 40 cm depth treatment is the highest（54.21%）,and that of 20 cm depth treatment is lowest;the N residual ration during 0–80 cm depth soil of 40 cm depth treatment is the highest（31.73%）,and that of 0 cm depth treatment is lowest. Thus,the 20 cm depth treatment can enhance the absorption and ability to transfer N to organs of pear trees,and reduce the nitrogen loss and residual in the soil in this study.