氮肥水平对不同土壤N2O排放的影响 |
摘要点击 3388 全文点击 1970 修订日期:2007-09-18 |
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中文关键词 N2O排放 氮肥; 稻麦轮作; 盆栽试验 |
英文关键词 N2O emission N fertilizer rice-wheat rotation period pot experiment |
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中文摘要 |
鉴于N2O排放量占施用氮肥量的比例即N2O排放系数还有很大不确定性,室外盆栽试验于2002~2003年选取3个供试土壤,各土壤设置对照和低、中、高氮肥水平,全年施尿素量 (以N计) 分别为334、 670和1 004 kg/hm2.结果表明,水稻生长季,各个土壤的N2O累积排放量与其对照相比的增加量在低、中、高氮肥水平间无明显差异;而小麦生长季,随氮肥施用量增加,各个土壤的N2O累积排放量与其对照相比的增加量在3种氮肥水平之间的差异显著.整个稻麦轮作系统,随氮肥用量的增加明显促进麦田N2O的排放.无论水稻或小麦生长季,对照3个土壤的N2O累积排放量并无显著差异,F土壤(江苏溧水)、G土壤(江苏涟水)和H土壤(江苏农科院)的N2O累积排放量,在水稻生长季分别为168、 127和146 mg/m2;小麦生长季,分别为134、 124和168 mg/m2.在施氮肥后,3个土壤的N2O排放量出现差异,如在中氮水平下,小麦生长季,F土壤、G土壤和H土壤N2O累积排放量分别为976、 744和626 mg/m2.稻麦轮作生长季内,在低氮与中氮2个水平下,不同土壤间N2O排放系数存在显著差异.以1个稻麦轮作周期为时间尺度,F土壤、G土壤和H土壤总的N2O排放系数分别为1.1%±0.23%、 0.75%±0.17%和1.01%±0.11%,表明不同土壤对N2O排放系数的影响不同. |
英文摘要 |
To investigate the effect of different urea incorporation amount in different soils on N2O emission, a pot experiment was carried in 2002-2003.Four treatments were designed as the control (without urea incorporation); low N fertilizer level(334 kg/hm2); middle N fertilizer level(670 kg/hm2); high N fertilizer level (1 004 kg/hm2). In rice growing season, compared to control, the increment of N2O emission accumulation flux of each soil has no obviously differences among three N fertilizer levels. Contrarily, in wheat-planted soils, there are remarkably differences among three N fertilizer levels. Without urea incorporation, there are no differences among N2O accumulation emission flux of three soils. During the rice growing season, N2O accumulation emission flux of F soil (jiangsu province, lishui), G soil (jiangsu province, lianshui) and H soil (jiangsu province, agriculture academy) are 168, 127 and 146 mg/m2,respectively. N2O accumulation emission flux of F soil, G soil and H soil is 134, 124 and 168 mg/m2, respectively, during wheat growing season. Incorporation of urea into different soils yielded different influence on N2O emission. For example, at middle-N fertilizer, N2O accumulation emission flux from F soil, G soil and H soil is 976, 744 and 626 mg/m2,respectively. During rice-wheat rotation period, significance differences exists among N2O emission factors of three soils, with the value of (1.1±0.23)%, (0.75±0.17%) and (1.01±0.11)%. Furthermore, under the high N fertilizer level, N2O emission factors of three soils had no significantly difference(p=0.3); while, the N2O emission factors existed difference among three soils under the low and middle N fertilizer level(F=6.25,p=0.01). |
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