不同耕作方式下冬小麦田N_2O排放特征的差异性研究  

Characteristic variations of N_2O flux in winter wheat field under different tillage methods

作　　者：陈晓龙[1,2] 杨威[1,2] 江波[3] 殷寒旭 杨小兵[1] 杨书运[1] 马友华[1] 

机构地区：[1]安徽农业大学资源与环境学院,安徽合肥230036 [2]农业部合肥农业环境科学观测试验站,安徽合肥230036 [3]安徽省发展和改革委员会经济研究院,安徽合肥230001

出　　处：《干旱地区农业研究》2016年第3期221-227,246,共8页Agricultural Research in the Arid Areas

基　　金：公益性行业(农业)科研专项(201103039)

摘　　要：采用静态箱—气相色谱法对空白对照(CK)、常规施肥(CG)、免耕(CB)、秸秆还田(CJ)4种处理小麦田的N_2O排放通量进行原位监测,同时测量土壤温度、水分及NH+4等相关影响因子的变化情况。研究结果表明:(1)4种处理方式下麦田N_2O排放通量具有明显的季节性变化规律,N_2O排放通量变化趋势基本一致,其中空白对照各处理N_2O的排放通量受季节性影响变化较小。(2)在小麦生长季,4种处理方式下的农田均表现为N_2O的排放源。与空白对照相比,常规耕作、免耕和秸秆还田处理下N_2O的排放总量分别增加了0.89 kg·hm^(-2)、0.41 kg·hm^(-2)和1.02 kg·hm^(-2)。(3)气温和土壤5 cm、10 cm温度与N_2O排放通量不存在显著的相关性,因而温度不是影响麦田N_2O排放的限制性因素。各处理N_2O排放通量与土壤水分均呈现正相关(P<0.05)。通过对比几次降水与施肥前后N_2O排放通量的关系,发现降水后施肥能显著减少N_2O排放。降水引起的土壤水分增加是影响N_2O排放通量剧烈变化的因素。(4)免耕和秸秆还田分别在N_2O减排与小麦增产方面效果最好。N_2O减排与小麦增产作为农业可持续发展的基本要求,秸秆还田处理效果最优。The N_2O emission fluxes and seasonal variations by four treatments including blank control（ CK）,conventional tillage（ CG）,no tillage（ CB）,and straw application tillage（ CJ） were sampled and measured by static chamber-gas chromatographic. The soil temperature,water content,NH＋4,Eh and other related factors were monitored at the same time. The results indicated that N_2O emission flux by four treatments showed significantly seasonal variations and each treatment displayed a consistent trend. However,emission flux of the blank control were less subjective to seasonal changes in volatility than others. In addition,during wheat growing season,all farmland treatments were N_2O emission sources. Compared with the blank control,the N_2O total emission fluxes by conventional tillage,no tillage and straw application tillage were increased by 0. 89 kg·hm- 2,0. 41 kg·hm- 2and 1. 02 kg·hm- 2,respectively. Moreover,air temperature and soil temperature at 5 cm and 10 cm layers were not related to N_2O emission flux,indicating that these were not the significant limiting factors as the wheat field N_2O emissions flux. N_2O emission fluxes by all treatments and soil moisture showed a positive correlation（ P 0.05）. By comparing the relationship between precipitation and pre and post fertilization,it was found that N_2O e-missions flux could be significantly reduced by fertilization after rains. The increase of water content caused by precipitation was the factor that affected the dramatic change of N_2O emissions flux. Furthermore,no tillage and straw application tillage had the best effects on N_2O emissions and wheat production among the four treatments. For N_2O abatement and wheat yield,straw application tillage is the most appropriate approach.

关 键 词：N2O排放 冬小麦田 耕作方式 土壤水分 温室气体 减排 

分 类 号：S181.3[农业科学—农业基础科学]