Impact of mineral N fertilizer application rates on N2O emissions from arable soils under winter wheat
Impact of mineral N fertilizer application rates on N2O emissions from arable soils under winter wheat
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DOI：
10.1007/s10705-014-9630-0
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发表时间：
2014-08
影响因子：
3.1
通讯作者：
Ulrike Lebender;M. Senbayram;J. Lammel;H. Kuhlmann
中科院分区：
文献类型：
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作者：
Ulrike Lebender;M. Senbayram;J. Lammel;H. Kuhlmann
氮肥是农田土壤中一氧化二氮(N2O)排放的主要来源。在德国西北部6个田间定位的冬小麦生育期内(~140d)，研究了施氮量与N2O排放的关系。氮肥以硝酸钙-铵-硝酸盐的形式施入，施氮量从0到400亿公斤/公顷−1不等。2010年进行了一次试验，2011年进行了三次试验，2012年进行了两次试验。此外，还在秋冬季(2012-2013年)对两个田间地点的收获后N2O排放进行了评估。排放因子(生长期)在0.10-0.37%之间变化。年N2O排放量在0.46%至0.53%之间，所有地点和年份的N2O排放量一直低于IPCC第一级默认值(1.0%)。在所有地点和年份，即使施氮量高于作物的氮素吸收，N2O与施氮量之间的关系也可用线性回归最好地描述。此外，还计算了两个田间地块每年每单位收获小麦籽粒的N2O排放量，以评估小麦籽粒生产的环境影响。产量尺度的N2O排放量遵循双曲线函数，当施氮量分别为127g/−1和150g/hm2/−1时，籽粒产量最低为177g/hm2，产量为191g/hm2，随后随施氮量的增加而增加。这一关系表明，与不施肥相比，小麦作物施肥并不一定通过N2O排放来损害环境。因此，提高氮肥利用效率可能是减少按产量计算的N2O排放的最佳管理实践。
Nitrogen fertilizers are a major source of nitrous oxide (N2O) emissions from arable soils. The relationship between nitrogen application rates and N2O emissions was evaluated during the growth period of winter wheat (~140 days) at six field sites in north-western Germany. Nitrogen was applied as calcium–ammonium–nitrate, with application rates ranging between 0 and 400 kg N ha−1. One trial was conducted in 2010, three trials in 2011 and two trials in 2012. Additionally, post-harvest N2O emissions were evaluated at two field sites during autumn and winter (2012–2013). The emission factors (during the growth period) varied between 0.10 and 0.37 %. Annual N2O emissions ranged between 0.46 and 0.53 % and were consistently lower across all sites and years than to the IPCC Tier 1 default value (1.0 %). Across all sites and years, the relationship between N2O and N application rate was best described by linear regression even if nitrogen amounts applied were higher than the nitrogen uptake of the crop. Additionally, annual N2O emissions per unit of harvested wheat grain were calculated for two field sites to assess the environmental impact of wheat grain production. Yield-scaled N2O emissions followed a hyperbolic function with a minimum of 177 and 191 g N2O–N t grain yield−1at application rates of 127 and 150 kg N ha−1, followed by an increase at higher N application rates. This relationship indicates that wheat crop fertilization does not necessarily harm the environment through N2O emissions compared to zero fertilization. Thus, improving nitrogen use efficiency may be the best management practice for mitigating yield-scaled N2O emissions.