Nitrous oxide emissions from fertilised UK arable soils: Fluxes, emission factors and mitigation
Nitrous oxide emissions from fertilised UK arable soils: Fluxes, emission factors and mitigation
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DOI：
10.1016/j.agee.2015.07.003
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发表时间：
2015-12-20
影响因子：
6.6
通讯作者：
Chadwick, D. R.
中科院分区：
文献类型：
--
作者：
Bell, M. J.;Hinton, N.;Chadwick, D. R.
农业土壤是一氧化二氮（N2O）的最大人为来源。强度是二氧化碳的298倍。由于农业用地占地球表面的40-50%，农业N2O排放可能对未来气候产生重大影响。人造氮肥的施用时间、数量和形式是控制N2O排放量的主要因素，人们正在研究各种方法来量化和减少这些排放。由于缺乏测量的一氧化二氮排放因子（EFs），因此大多数国家报告一氧化二氮排放量时使用的是IPCC的第一级方法，即无论土壤类型、气候或地点如何，都将1%的EF应用于矿质土壤。本研究的目的是通过确定N2O EFs是否应随土壤类型和农业气候带而变化，从实验中产生证据，以有助于改善英国的N2O农业库存。还对缓解方法进行了研究，包括评估硝化抑制剂双氰胺（DCD）的影响、更频繁地施用小剂量肥料以及不同施用量和不同形式的人造氮肥的影响。在2011/2012年的12个月里，在苏格兰的一个农田和英格兰的两个农田测量了一氧化二氮的排放量，同时测量了土壤和环境变量。测定了不同肥料处理的作物产量，并计算了不同肥料处理的排放强度。在苏格兰地区测量了硝酸铵（AN）肥料用量范围内的最大平均年累积排放量（2301 g N2O-N ha(-1)），经历了822毫米降雨量，而在英国地区，累积年排放量较低（分别为929和1152 g N2O-N ha(-1)），为418毫米和472毫米。气候和土壤矿物氮影响N2O排放，需要多种因素同时发生才能产生最大通量。排放与肥料氮含量有关；然而，这种趋势并不是线性的。不同地点间氮化铵处理的电场效应不同，但在两个英国地点均远低于IPCC使用的1%值，最低可达0.20%。DCD减少了所有站点的氨和尿素产生的一氧化二氮排放和产量规模排放。更频繁、更小剂量的施用氮磷酰胺减少了所有地点的排放，然而，肥料类型（氮磷酰胺或尿素）没有影响。站点间年平均累积排放量的显著差异反映了降雨量的差异，这表明可以考虑特定地点或降雨量驱动的排放估算。(C) 2015 Elsevier B.V.版权所有
Cultivated agricultural soils are the largest anthropogenic source of nitrous oxide (N2O), a greenhouse gas approx. 298 times stronger than carbon dioxide. As agricultural land covers 40-50% of the earth's surface agricultural N2O emissions could significantly influence future climate. The timing, amount and form of manufactured nitrogen (N) fertiliser applied to soils are major controls on N2O emission magnitude, and various methods are being investigated to quantify and reduce these emissions. A lack of measured N2O emission factors (EFs) means that most countries report N2O emissions using the IPCC's Tier 1 methodology, where an EF of 1% is applied to mineral soils, regardless of soil type, climate, or location. The aim of this research was to generate evidence from experiments to contribute to improving the UK's N2O agricultural inventory, by determining whether N2O EFs should vary across soil types and agroclimatic zones. Mitigation methods were also investigated, including assessing the impact of the nitrification inhibitor (NI) dicyandiamide (DCD), the application of more frequent smaller doses of fertiliser, and the impact of different rates and forms of manufactured N fertiliser. Nitrous oxide emissions were measured at one cropland site in Scotland and two in England for 12 months in 2011/2012, along with soil and environmental variables. Crop yield was also measured, and emission intensities were calculated for the contrasting fertiliser treatments. The greatest mean annual cumulative emissions from a range of ammonium nitrate (AN) fertiliser rates were measured at the Scottish site (2301 g N2O-N ha(-1)), which experienced 822 mm rainfall compared to 418 mm and 472 mm at the English sites, where cumulative annual emissions were lower (929 and 1152 g N2O-N ha(-1), respectively). Climate and soil mineral N influenced N2O emissions, with a combination of factors required to occur simultaneously to generate the greatest fluxes. Emissions were related to fertiliser N rate; however the trend was not linear. EFs for AN treatments varied between sites, but at both English sites were much lower than the 1% value used by the IPCC, and as low as 0.20%. DCD reduced AN- and urea-generated N2O emissions and yield-scaled emissions at all sites. AN application in more frequent smaller doses reduced emissions at all sites, however, the type of fertiliser (AN or urea) had no impact. A significant difference in mean annual cumulative emissions between sites reflected differences in rainfall, and suggests that location specific or rainfall driven emission estimates could be considered. (C) 2015 Elsevier B.V. All rights reserved.