施氮深度对‘黄金梨’树氮素吸收、分配及利用效率的影响

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。

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

In this field experiment，seven-year-old pear trees（Pyrus pyrifolia‘Hwangkumbae’） were treated by 15N-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 15N 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 15N 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.