【作者】 李天安； 樊小林； 刘芳； 吕雪娟；

【Author】 Tianan Li, Xiaoling Fan, Fang Liu, Xuejuan Lu(College of Resources and Environmental Science. South China Agriculture University, Wushan.Guangzhou 510642)

【机构】 华南农业大学资环学院肥料与平衡施肥研究室；

【摘要】 通过大田与盆试验以及室内分析,研究覆膜旱种稻田生态系统N2O排放的机理。结果表明,大田水稻全生育期内覆膜旱种稻田N2O的平均排放量(0.96ug.m2.h-1)远远大于常规水稻田的排放量(0.052ug.m-2.h-1)。盆栽试验覆膜旱种稻田土壤N2O平均排放量是常规水田的3.31倍。不论是旱种还是水田,只要增加硝态氮源,土壤N2O的排放就极显著增加。氮素形态对土壤N2O排放量贡献的大小顺序为硝态氮>铵态氮>酰胺态氮>土壤故有氮。硝态氮源处理的N2O排放量分别是铵态氮和尿素的10.82和15.54倍。覆膜旱种稻田土壤中氮素的硝化、硝态氮积累及其反硝化、反硝化产生的N2O及时向大气的扩散等协同作用是覆膜旱种条件下稻田N2O排放量显著增加的机理。更多还原

【Abstract】 Both field and pot experimentation as well as laboratory analysis were applied to test N2O emission and study its mechanism under normal waterlog paddy field and GCRPS field being field covered by plastic film and soil moisture in 70% to 90% of file holding capacity. Field experiment result showed that N3O flux from the GCRPS paddy field (0.96 mg-m-2.h-1) was significantly higher than that of the normal waterlog paddy field (0.052 mg. m-2.h-1). The N2O flux of the GCRPS field was 3.31 times of the normal waterlog paddy field in pot experimentation. No matter what the soil moisture treated, being with waterlog in normal paddy or upland condition in GCRPS field, once nitrate as nitrogen fertilizer source. N2O emission increased remarkably. The contribution of N form to N2O emission was in the flowing order, NO3- > NH4+ > CO(NH2)2. N2O flux in treatment of nitrate as N source was 10.82 and 15.54 times that of ammonium and urea as N sources respectively. The mechanism of GCRPS stimulating emission of nitro dioxide is that the upland condition is favorable soil N to turn into nitrate, being main source of denitrification to produce nitro oxide. The condition is also beneficial to promote N2O pass through the soil into atmosphere and to block the process of N2O to deoxidize into N2.更多还原