Nitrous oxide emissions from cattle excreta applied to a Scottish grassland: Effects of soil and climatic conditions and a nitrification inhibitor
Nitrous oxide emissions from cattle excreta applied to a Scottish grassland: Effects of soil and climatic conditions and a nitrification inhibitor
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DOI：
10.1016/j.scitotenv.2014.12.008
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发表时间：
2015-03-01
影响因子：
9.8
通讯作者：
Chadwick, D. R.
中科院分区：
文献类型：
--
作者：
Bell, M. J.;Rees, R. M.;Chadwick, D. R.
排泄到草地上的粪便和尿液是一氧化二氮（N2 O）的主要来源。这些N2 O排放源于反刍动物对摄入的氮（N）的低效利用，以及牧场无法利用沉积的N。奶制品和肉类消费量的预测增长意味着需要量化N2 O排放量，并调查减排机制。三个12个月的“季节性”实验进行了在Crichton，苏格兰西南部，N2 O排放量测量牛尿，粪，人工尿和尿+硝化抑制剂（NI），双氰胺（DCD）的应用。三个应用时间是“春季”，“夏季”和“秋季”，代表早，中，晚放牧季节。N2 O排放量的测量从静态室为12个月。目的是量化牛排泄物的排放量，确定其对施用季节的依赖性，以及粪便和尿液各自对排泄物排放总量的贡献。从NI修正尿的测量进行了评估DCD的潜力，作为一种减排工具。排放量与IPCC的默认排放因子（EF）2%的牛排泄的氮进行了比较。夏季施用时，尿液的平均年累积排放量最高（5，034 g N2 O-N ha（-1）），春季（1，903 g N2 O-N ha（-1））和秋季（2，014 g N2 O-N ha（-1））施用的排放量较低，这很可能是由于夏季温度较高和土壤湿度有利于硝化和反硝化。当夏季施用排泄物时，尿液（1.1%）的EFs显著高于粪便（0.2%），且EFs随施用季节而变化，但在所有实验中均低于IPCC默认值2%。这些结果支持降低和分解为个人的粪便和尿液的EF。将DCD添加到尿液中不会显著减少排放量，这表明需要对其作为缓解选择进行更多的研究。(C)2014爱思唯尔有限公司版权所有。
Dung and urine excreted onto grasslands are a major source of nitrous oxide (N2O). These N2O emissions stem from inefficient utilisation of nitrogen (N) ingested by ruminants, and the inability of pasture to utilise the deposited N. Predicted growth in dairy and meat consumption means that there is a requirement to quantify N2O emissions, and investigate emission reduction mechanisms. Three 12 month 'seasonal' experiments were undertaken at Crichton, SW Scotland, where N2O emissions were measured from applications of cattle urine, dung, artificial urine and urine + a nitrification inhibitor (NI), dicyandiamide (DCD). The three application timings were 'spring', 'summer' and 'autumn', representative of early-, mid- and late grazing seasons. N2O emissions were measured from static chambers for 12 months. The aim was to quantify emissions from cattle excreta, and determine their dependence on the season of application, and the respective contribution of dung and urine to total excreta emissions. Measurement from NI amended urine was made to assess DCD's potential as an emission mitigation tool. Emissions were compared to the IPCC's default emission factor (EF) of 2% for cattle excreted N. Mean annual cumulative emissions from urine were the highest when applied in summer (5034 g N2O-N ha(-1)), with lower emissions from spring (1903 g N2O-N ha(-1)) and autumn (2014 g N2O-N ha(-1)) application, most likely due to higher temperatures and soil moisture conducive to both nitrification and denitrification in the summer months. Calculated EFs were significantly greater from urine (1.1%) than dung (0.2%) when excreta was applied in summer, and EFs varied with season of application, but in all experiments were lower than the IPCC default of 2%. These results support both lowering and disaggregating this EF into individual EFs for dung and urine. Addition of DCD to urine caused no significant reduction in emissions, suggesting that more research is required into its use as a mitigation option. (C) 2014 Elsevier B.V. All rights reserved.