Impact of dicyandiamide on emissions of nitrous oxide,nitric oxide and ammonia from agricultural field in the North China Plain

Nitrous oxide（N2O）, nitric oxide（NO） and ammonia（NH3） emissions from an agricultural field in the North China Plain were compared for three treatments during a whole maize growing period from 26 June to 11 October, 2012. Compared with the control treatment（without fertilization, designated as CK）, remarkable pulse emissions of N2O, NO and NH3 were observed from the normal fertilization treatment（designated as NP） just after fertilization, whereas only N2O and NH3 pulse emissions were evident from the nitrification inhibitor treatment（designated as ND）. The reduction proportions of N2O and NO emissions from the ND treatment compared to those from the NP treatment during the whole maize growing period were 31% and 100%, respectively. A measurable increase of NH3 emission from the ND treatment was found with a cumulative NH3 emission of 3.8 ± 1.2 kg N/ha,which was 1.4 times greater than that from the NP treatment（2.7 ± 0.7 kg N/ha）.