华东稻麦轮作生态系统冬小麦田NO排放观测研究

在采用基于箱法的自动观测技术对华东稻麦轮作生态系统的整个小麦生育期进行了ＮＯ排放全天候连续观测基础上，本文讨论了华东麦田ＮＯ排放的季节变化和变化特征以及温度、土壤湿度、施肥和植物生长的影响，华东冬小麦田的ＮＯ排放很明显地表现为”春高、秋低、冬无“的季节变化趋势，温度是决定其季节变化基本形式的首要因素，尽管施氮肥可以增加当季ＮＯ排放５－７倍，但却能不改变ＮＯ排放的季节变化格局，在植物生长活动较弱的情

NO emission from winter wheat fields of rice-wheat rotation ecosystem in southeast China

Measurements of NO emission from the winter wheat field of rice-wheat rotation ecosystem in southeast China during the whole period of wheat growth show that a higher NO emission was observed in spring than in autumn, and almost no emission in winter could be detected. Temperature was the most important factor determining the seasonal variation pattern of NO emission. Although the N fertilization might enlarge NO emission by a factor of 5-7, it could not modify the seasonal variation pattern. During the period of relatively weak plant activity, the diurnal variation pattern, with the maximum emission at 9:00-14:00, was determined by temperature. When plants luxuriated, however, the competition of NH4+ by plant uptake and by microbial nitrification led to a night-peak variation pattern, in which, the maximum diurnal emission usually occurred during 18:00 and 4:00 of next day, and the minimum at 8:00-16:00.