Nitrogen fertiliser interactions with urine deposit affect nitrous oxide emissions from grazed grasslands
Nitrogen fertiliser interactions with urine deposit affect nitrous oxide emissions from grazed grasslands
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DOI：
10.1016/j.agee.2019.106784
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发表时间：
2020-03
期刊：
影响因子：
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通讯作者：
J. Maire;D. Krol;D. Pasquier;N. Cowan;U. Skiba;R. Rees;D. Reay;G. Lanigan;K. Richards
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文献类型：
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作者：
J. Maire;D. Krol;D. Pasquier;N. Cowan;U. Skiba;R. Rees;D. Reay;G. Lanigan;K. Richards
放牧牧场上沉积的牛排泄物占全球人为一氧化二氮(N2O)排放量的五分之一。主要的氮(N)来源之一是放牧动物的尿液沉积，这在很小的区域内造成了非常大的N负荷。本小区研究的主要目的是确定施氮肥和奶牛尿沉淀物是否存在协同作用，从而增加N2O排放，以及这种相互作用如何受施肥期的影响。化肥(硝酸铵钙)和尿液配施显着增加了N2O的累积排放量和N2O排放因子，春季从0.35%增加到0.74%，夏季从0.26%增加到0.52%。相比之下，只使用化肥(春季为0.31%，夏季为0.07%)或尿液(春季为0.33%，夏季为0.28%)的EFS较低。秋季，N2O排放量大于其他季节，与单独使用尿液或氮肥的排放量相比，差异无统计学意义(EF范围为0.72~0.83，p值为0.05)。没有显著的协同效应可能是由于天气条件，特别是秋季施药前三天和施药后三天的降雨。这项研究表明，在温室气体排放清单中，需要考虑氮肥和尿液沉积的交互作用，以及施氮肥对N2O排放的时机。
Cattle excreta deposited on grazed pastures are responsible for one fifth of the global anthropogenic nitrous oxide (N2O) emissions. One of the key nitrogen (N) sources is urine deposited from grazing animals, which contributes to very large N loadings within small areas. The main objective of this plot study was to establish whether the application of N fertiliser and urine deposit from dairy cows synergistically interacts and thereby increases N2O emissions, and how such interaction is influenced by the timing of application. The combined application of fertiliser (calcium ammonium nitrate) and urine significantly increased the cumulative N2O emissions as well as the N2O emission factor (EF) from 0.35 to 0.74 % in spring and from 0.26 to 0.52 % in summer. By contrast, EFs were lower when only fertiliser (0.31 % in spring, 0.07 % in summer) or urine was applied (0.33 % in spring, 0.28 % in summer). In autumn, N2O emissions were larger than in other seasons and the emissions from the combined application were not statistically different to those from either the separately applied urine or N fertiliser (EF ranging from 0.72 to 0.83, p-value < 0.05). The absence of significant synergistic effect could be explained by weather conditions, particularly rainfall during the three days prior to and after application in autumn. This study implies that the interactive effects of N fertilisation and urine deposit, as well as the timing of the application on N2O emission need to be taken into account in greenhouse gas emission inventories.