研究报告
王连峰,蔡祖聪.淹水与湿润水分前处理对旱地酸性土壤氧化亚氮和二氧化碳排放的影响[J].环境科学学报,2011,31(8):1736-1744
淹水与湿润水分前处理对旱地酸性土壤氧化亚氮和二氧化碳排放的影响
- Nitrous oxide and carbon dioxide emissions from upland acidic soils under flooding and moistening pretreatments
- 基金项目：国家自然科学基金项目(No.40971145,40830531);土壤与农业可持续发展国家重点实验室开放基金(No.0812000050)
- 作者
- 单位
- 王连峰
- 1. 中国科学院南京土壤研究所 土壤与农业可持续发展国家重点实验室,南京 210008;
2. 大连交通大学环境与化学工程学院 环境科学与技术辽宁省高校重点实验室,大连 116028
- 蔡祖聪
- 中国科学院南京土壤研究所 土壤与农业可持续发展国家重点实验室,南京 210008
- 摘要：田间采集含水量为21.6%土壤最大田间持水量(Water holding capacity,WHC)的新鲜旱地红砂土,室温下分别进行湿润(土样M,调节含水量为40%WHC)和淹水(土样F)两种水分前处理,保存110 d后,将土样M和土样F的含水量再分别调至40%、70%和100%WHC,在25℃下培育120 h,设置不通和通入10% (V/V)乙炔的处理,研究水分前处理对土壤氧化亚氮(N2O)产生过程和排放量及二氧化碳(CO2)排放量的影响.结果显示,在40%和70%WHC下,土样M的N2O排放量分别是土样F的15.3和5.63倍,CO2排放量分别是土样F的1.31和0.90倍(p<0.05),而在100%WHC下,土样M的N2O排放量仅为土样F的2.1%,CO2排放量未受前期水分处理的影响.在40%和70%WHC下,通入乙炔对土样M的N2O排放量未产生显著性影响,但增加了土样F的N2O排放量(p<0.05),在100%WHC下,通入乙炔显著降低了土样M的N2O排放量,却未对土样F的N2O排放量产生显著性影响,培养结束后,土样M的硝态氮含量显著增加,而土样F的硝态氮含量显著降低(p<0.05).这些结果表明,湿润前处理的土样M主要进行异养硝化作用,而淹水前处理的土样F主要进行反硝化作用产生N2O,即水分前处理改变了土壤N2O的产生过程.
- Abstract：Laboratory incubation experiments were conducted to investigate how water pretreatments affect nitrous oxide (N2O) and carbon dioxide (CO2) emissions from an arable Argosols.The soil samples, taken from southern China, had an initial soil water content of 21.6% of water holding capacity (WHC).These samples were imposed with two water pretreatments for 110 days: One with water content raised to 40% of WHC (sample M) and the other maintained under flooded conditions (sample F).Subsequently, for each of the water pretreatments, there were three water content treatments: 40%, 70% and 100% of WHC.Then these samples were incubated at 25℃ with or without 10% (V/V) acetylene for 120 h.Air samples from the headspace of each incubator were measured using GC.The results showed the N2O emissions from sample M were 15.3 and 5.63 times (p<0.01) and CO2 emissions were 1.30 and 0.90 times (p < 0.05) as much as from sample F at soil water contents of 40% and 70%WHC, respectively.At 100%WHC, N2O emission from the sample M was only 2.1% that from sample F, and there was no significant difference in CO2 emission between the water pretreatments.At 40% and 70%WHC, acetylene addition had no significant effect on N2O emission from sample M, but significantly increased N2O emission from sample F (p<0.05).At 100%WHC, however, the reverse was true.After incubation, the content of nitrate significantly increased in sample M, but decreased in sample F (p<0.05).These findings suggest that the main N2O production process was heterotrophic nitrification in sample M and denitrification in sample F.Therefore, water pretreatment changed the N2O production processes.
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