Emissions of nitrous oxide from the leaves of grasses
Emissions of nitrous oxide from the leaves of grasses
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DOI：
10.1007/s11104-013-1879-6
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发表时间：
2014-01-01
期刊：
影响因子：
4.9
通讯作者：
Luo, Dongwen
中科院分区：
文献类型：
--
作者：
Bowatte, Saman;Newton, Paul C. D.;Luo, Dongwen
畜牧业的一氧化二氮（N2 O）排放被认为是土壤硝化和反硝化过程中微生物活动的结果。然而，最近的研究表明，植物冠层是向大气排放N2 O的一个潜在的重要来源。了解植物排放的程度和机制可能会提供新的减排机会，因为目前的选择只针对土壤微生物过程。我们开发了一个实验装置和协议，以划分N2 O的树叶和土壤之间的排放和测量10种常见的草在新西兰牧场的排放。箱的设计使我们能够确定可测量的变化，N2 O浓度在一段时间内，h，区分0.001 ~ 0.25 mg N2 O-N/m（2）叶面积/h的排放范围。有10倍的物种之间的变化; Holcus lanataus，多年生黑麦草和百喜草具有最高的叶片N2 O排放量和早熟禾最低。草不排放N2 O从他们的叶子和率，这发生在草种之间的变化。排放量似乎并不来自植物叶片中N2 O的形成，但更可能反映了N2 O从土壤中的运输。排放率的差异似乎是由于植物对土壤中N2 O形成率的影响，而不是通过植物的运输率。
Nitrous oxide (N2O) emissions from pastoral agriculture are considered to originate from the soil as a consequence of microbial activity during soil nitrification and denitrification. However, recent studies have identified the plant canopy as a potentially significant source of N2O emissions to the atmosphere. Understanding the extent and mechanisms of plant emissions may provide new mitigation opportunities as current options only target soil microbial processes.We developed an experimental apparatus and protocol to partition N2O emissions between the leaves of grasses and the soil and measured emissions from ten common grass species found in New Zealand pastures.The chamber design enabled us to identify measurable changes in N2O concentration over a period of 1 h and to distinguish a range of emissions from 0.001 to 0.25 mg N2O-N/m(2) leaf area/h. There was a 10-fold variation among species; Holcus lanataus, Lolium perenne and Paspalum dilatatum had the highest leaf N2O emissions and Poa annua the lowest.Grasses do emit N2O from their leaves and the rate that this occurs varies among grass species. The emission does not appear to arise from formation of N2O in plant leaves but more likely reflects transport of N2O from the soil. Differences in emission rates appear to arise from a plant influence on the rate of formation of N2O in the soil rather than the rate of transportation through the plant.