中文摘要：

在玉米生长季,采用温室盆栽试验,利用分根箱法和根去除法,研究了氮肥对土壤呼吸、土壤基础呼吸、根系呼吸和根际微生物呼吸的影响.试验设4个处理：不种植玉米不施氮肥（CKO）、不种植玉米施氮肥（CKN）、种植玉米不施氮肥（MO）和种植玉米施氮肥（MN）.结果表明：不种植玉米处理（CKN和CKO）土壤呼吸速率（土壤基础呼吸）为13.41～77.27 mg C.m-2.h-1,施用氮肥对土壤基础呼吸没有显著影响;种植玉米条件下,施氮处理（MN）的平均土壤呼吸速率为138.54 mg C.m-2.h-1,显著高于不施氮处理（MO）,增幅达17.7%,尤其在玉米的抽穗期和开花期增幅明显.施氮肥处理土壤基础呼吸、根系呼吸和根际微生物呼吸对土壤呼吸的贡献率分别为36.2%、45.9%和17.9%,而不施氮肥处理分别为35.5%、36.9%和37.6%.

英文摘要：

In order to understand how nitrogen（N） fertilization affects soil respiration,a pot experiment with splitting-root compartment and by root-cutting was conducted in a greenhouse.The experiment had four treatments,i.e.,unplanted and N-unfertilized（CKO）,unplanted but fertilized with 150 mg N·kg-1（CKN）,planted maize（Zea mays L.） but N-unfertilized（MO）,and planted maize and fertilized with 150 mg N·kg-1（MN）.Soil respiration,soil basal respiration,root respiration,and rhizospheric microbial respiration were measured simultaneously.In unplanted soils（treatments CKO and CKN）,soil respiration rate（soil basal respiration） ranged from 13.41 to 77.27 mg C·m-2·h-1,and N fertilization had less effect;while in planted soils,the averaged soil respiration rate in treatment MN amounted to 138.54 mg C·m-2·h-1,and was 17.7% higher（P0.05） than that in treatment MO.This increment mainly occurred at tasselling and flowering stages.During maize growth season,the contribution of soil basal respiration,root respiration,and rhizospheric microbial respiration to soil respiration in treatments MN and MO was 36.2%,45.9%,and 17.9%,and 35.5%,36.9%,and 37.6%,respectively.