摘要
以贵州省的玉米－油菜轮作田、大豆－冬小麦轮作和休耕地为研究对象，采用密闭箱－气相色谱法，对整个轮作期的土壤Ｎ２Ｏ释放进行观测，初步研究我国亚热带旱田的Ｎ２Ｏ释放特征．实验研究结果表明，３试验田Ｎ２Ｏ释放通量具有相同的规律性日变化形式，秋收作物达通量极大值的时间比越冬作物滞后２ｈ～３ｈ，气温是控制Ｎ２Ｏ通量日变化的主要环境因子：３试验田Ｎ２Ｏ释放通量（以Ｎ２Ｏ中的Ｎ计）分别在９．８１～４３３．１１，４．００～１８０．４１和９．７４～２８２．００μｇ·ｍ － ２·ｈ－ １，高于我国水田和北方旱田的Ｎ２Ｏ释放通量；进一步分析表明，３试验田Ｎ２Ｏ释放通量具有相同的季节变化模式，Ｎ２Ｏ 释放峰受降雨事件的直接影响，Ｎ２Ｏ通量与降雨量和土壤湿度间有显著的正相关性。
Three fields including a corn rape rotation field,a soybean winter wheat rotation field and a fallow land were chosen as study plots to measure N 2O flux from soils using close chamber GC method during crop rotation,the purpose of this research was to study the characteristics of N 2O flux.The results indicated the shapes of N 2O diurnal variation were similar between above three fields,the time which N 2O flux reached the highest was 2 or 3 hours later from corn and soybean fields than from rape and winter wheat fields,and air temperature was the key factor influencing the diurnal variation of N 2O flux.The ranges of N 2O flux(as N in N 2O)from above three fields were 9.81～433.11,4.00～180.41 and 9.74～282.00μg·m -2 ·h -1 respectively,they were higher than fluxes from upland soils in North China.Furthermore,the seasonal variation characteristics of N 2O flux from above three fields were homologous,N 2O flux pulses were produced and driven by rainfall events directly,the relativity between N 2O flux and precipitation and soil's moisture were positive remarkably,but the relativity was not important between N_2O flux and temperature.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2000年第1期7-11,共5页
Environmental Science
基金
国家自然科学基金
