农田NO排放的自动观测

Automatical Measurement of NO Emission from Croplands

详细介绍农田ＮＯ排放自动观测的方法原理、系统整体构造及电路和气路配置，并讨论了观测结果的可靠性．同时，还就已取得的一些初步研究结果进行了分析．对华东秋、冬季麦田的ＮＯ排放进行自动连续观测的结果表明，秋季麦田的ＮＯ排放具有与温度几乎完全同步的日变化规律．ＮＯ排放的季节变化也十分明显．秋季的平均ＮＯ排放通量约为冬季的６—１５倍，且施氮肥１１４ｋｇｈｍ－２纯氮的ＮＯ排放量要比对照处理高２—７倍，温度和施肥是影响华东秋。

The principle,structure and procedure of an automated system for the measurement of NO emission from croplands was described in detail.Some experimental results taken from wheat fields of Southeast China with this automated system were also discussed.In this study,the diurnal variation of NO emission from wheat fields occurs in late autumn was found to be similar with that of temperature.Meanwhile,a seasonal variation of NO emission was obviously observed,with the mean value of NO emission fluxes measured in late autumn about 6—15 times higher than that in winter.Additionally,the seasonally total amount of NO emission from a plot with N fertilization at a rate of 114kg·hm -2 was as 2—7 times as that from the plot without N fertilization.Such results mean that temperature and application of N fertilizer are two key factors which regulate the NO emission from wheat fields in late autumn and in winter.