免耕对旱地春小麦成熟期CO_2和N_2O排放日变化的影响  

Effects of no-tillage on daily dynamics of CO_2 and N_2O emission from spring wheat field during mature stage

作　　者：刘博[1] 黄高宝[1] 高亚琴[2] 李卿沛[1] 黄涛[1] 

机构地区：[1]甘肃农业大学农学院,甘肃兰州730070 [2]甘肃农业大学资源与环境学院,甘肃兰州730070

出　　处：《甘肃农业大学学报》2010年第1期82-87,共6页Journal of Gansu Agricultural University

基　　金：国家科技支撑计划项目(2006BAD15B06);国家自然基金项目(40771132)

摘　　要：利用静态箱/气相色谱法对黄土高原旱地进行为期7a的免耕和常规耕作条件下春小麦成熟期农田生态系统CO2和N2O排放通量日变化进行了研究.结果表明:春小麦成熟期CO2和N2O的排放具有明显的日变化特征.CO2排放通量明显表现为常规耕作>免耕(除16∶00时观测值外),日最高排放值出现在14∶00,最低排放值出现在3∶00;N2O排放通量在10∶00、18∶00、22∶00时,表现为常规耕作>免耕,其余观测时段均表现为免耕>常规耕作.CO2和N2O排放通量均与地表温度、5cm地温和气温呈极显著正相关性,且常规耕作与免耕处理条件下,CO2排放通量与气温的相关系数最高,均为0.95,呈指数函数关系;N2O排放通量与地表温度的相关系数最高,分别为0.86和0.88,呈线性函数关系.Daily dynamics of CO2 and N2O emission from farmland ecosystem in spring wheat field at mature stage were measured by static chamber-gas chromatographic techniques under normal tillage and no-tillage for seven years in dry land of Loess Plateau.The results showed that daily dynamics of CO2 and N2O emission in spring wheat field at mature stage changed remarkably.CO2 emission flux under normal tillage was obvious higher than that under no-tillage（except measured value at 16∶00 p.m）,the maximal emission flux of CO2 appeared at 14∶00 p.m,and the minimum emission appeared at 3∶00 a.m;N2O emission flux under normal tillage was higher than that of no-tillage treatment during the whole day except at 10∶00 a.m,18∶00 p.m and 22∶00 p.m.Temperature was the important factor influencing the variation of CO2 and N2O emission.CO2 and N2O emission were significantly related to land surface temperature,soil temperature at the depth of 5 cm and air temperature.The correlation coefficients were 0.95 between CO2 flux and air temperature both under normal tillage and no-tillage,there was a significant exponential correlation between CO2 flux and air temperature;N2O flux were significant related to land surface temperature under normal tillage and no-tillage,the correlation coefficients were 0.86 and 0.88 respectively.There was a linear relationship between N2O emission flux and soil temperature.

关 键 词：春小麦 温室气体 黄土高原 免耕 

分 类 号：S512.12[农业科学—作物学]