稻麦轮作生态系统中土壤湿度对N_2O产生与排放的影响  

Impact of soil humidity on N_2O production and emission from a rice-wheat rotation ecosystem

作　　者：郑循华[1] 王明星[1] 王跃思[1] 沈壬兴[1] 龚宴邦 骆冬梅 张文[1] 金继生 李老土 

机构地区：[1]中国科学院大气物理研究所,江苏省吴县市农业科学研究所

出　　处：《应用生态学报》1996年第3期273-279,共7页Chinese Journal of Applied Ecology

基　　金：中国科学院大气物理研究所大气边界层物理与大气化学国家重点实验室基金

摘　　要：通过对太湖地区稻麦轮作生态系统的Ｎ２Ｏ排放及土壤湿度进行系统观测和开展一系列模拟实验，研究了降雨和土壤湿度对Ｎ２Ｏ排放和产生过程的影响．结果表明，春季和秋季麦田Ｎ２Ｏ排放与降雨量呈明显正相关，但水稻田和冬季麦田的Ｎ２Ｏ排放不受降雨影响．稻麦轮作周期内的Ｎ２Ｏ排放较强烈地受土壤湿度制约，土壤湿度为田间持水量的９７～１００％或８４～８６％ＷＦＰＳ（土壤体积含水量与总孔隙度的百分比）时，Ｎ２Ｏ排放最强，低于此湿度范围时，Ｎ２Ｏ排放通量与土壤湿度呈正相关，反之，则呈负相关．田间Ｎ２Ｏ排放随土壤湿度的变化形式与模拟条件下培养土壤样品的Ｎ２Ｏ产生率变化非常相似，但前者的最佳湿度范围比后者窄，而且偏小．Based on the in-situ measurement of soil humidity and N2O emission from a rice-wheat rotation ecosystem and on the simulated experiment in laboratory,the impact of precipitation and soil humidity on N2O production and emission is studied.The results show that the N2O emission from wheat field is positively correlated with precipitation in spring and autumn but not in winter,and that from rice field is not influenced by precipitation.Within a cycle of rice-wheat rotation, N2O emission is intensively affected by soil humidity.97～100% of soil water holding capacity (i.e.,84～86% of WFPS) leads to a maximum N2O emission.When the soil humidity is lower than this range,there is a positive correlation between N2O emission flux and soil humidity, and on the contrary,there is a negative one.The variation pattern of N2O emission with soil humidity is similar both under field and under simulated condition, although under the former one,the optimum humidity range for N2O emission is lower.

关 键 词：稻麦轮作生态系 作物生态 土壤湿度 一氧化二氮 

分 类 号：S344.13[农业科学—作物栽培与耕作技术] S314[农业科学—农艺学]