title: Effects of long-term amendment of organic manure and nitrogen fertilizer on nitrous oxide emission in a sandy loam soil.
abstract: To understand the effects of long-term amendment of organic manure and N fertilizer on N2O emission in the North China Plain, a laboratory incubation at different temperatures and soil moistures were carried out using soils treated with organic manure (OM), half organic manure plus half fertilizer N (HOM), fertilizer NPK (NPK), fertilizer NP (NP), fertilizer NK (NK), fertilizer PK (NK) and control (CK) since 1989. Cumulative N2O emission in OM soil during the 17 d incubation period was slightly higher than in NPK soil under optimum nitrification conditions (25 degrees C and 60% water-filled pore space, WFPS), but more than twice under the optimum denitrification conditions (35 degrees C and 90% WFPS). N2O produced by denitrification was 2.1-2.3 times greater than that by nitrification in OM and HOM soils, but only 1.5 times greater in NPK and NP soils. These results implied that the long-term amendment of organic manure could significantly increase the N2O emission via denitrification in OM soil as compared to NPK soil. This is quite different from field measurement between OM soil and NPK soil. Substantial inhibition of the formation of anaerobic environment for denitrification in field might result in no marked difference in N2O emission between OM and NPK soils. This is due in part to more rapid oxygen diffusion in coarse textured soils than consumption by aerobic microbes until WFPS was 75% and to low easily decomposed organic C of organic manure. This finding suggested that addition of organic manure in the tested sandy loam might be a good management option since it seldom caused a burst of N2O emission but sequestered atmospheric C and maintained efficiently applied N in soil.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. wxding@issas.ac.cn
authors.forename: Wei-xin
authors.initials: WX
authors.lastname: Ding
authors.forename: Lei
authors.initials: L
authors.lastname: Meng
authors.forename: Zu-cong
authors.initials: ZC
authors.lastname: Cai
authors.forename: Feng-xiang
authors.initials: FX
authors.lastname: Han
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002245:Carbon Dioxide / Q000032:analysis*; D005308:Fertilizers; D008372:Manure; D009566:Nitrates / Q000032:analysis; D009584:Nitrogen; D009609:Nitrous Oxide / Q000032:analysis*; D010758:Phosphorus; D011188:Potassium; D000644:Quaternary Ammonium Compounds / Q000032:analysis; D012822:Silicon Dioxide; D012987:Soil / Q000032:analysis; D012988:Soil Microbiology; D013696:Temperature; D014867:Water / Q000032:analysis
chemical_list: D000393:Air Pollutants; D005308:Fertilizers; D008372:Manure; D009566:Nitrates; D000644:Quaternary Ammonium Compounds; D012987:Soil; D014867:Water; D002245:Carbon Dioxide; D010758:Phosphorus; D012822:Silicon Dioxide; D009609:Nitrous Oxide; D009584:Nitrogen; D011188:Potassium