A geostatistical approach to identify and mitigate agricultural nitrous oxide emission hotspots.
A geostatistical approach to identify and mitigate agricultural nitrous oxide emission hotspots.
复制标题
识别和减轻农业一氧化二氮排放热点的地统计方法。
DOI：
10.1016/j.scitotenv.2016.08.094
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
R. Venterea
中科院分区：
文献类型：
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作者：
Peter A. Turner;T. Griffis;D. J. Mulla;John M. Baker;John M. Baker;R. Venterea;R. Venterea
一氧化二氮（N2O）是一种具有严重环境代价的痕量气体，其人为排放量在施用氮肥的农业土壤中最大。然而，精确的N2O排放量估计在精细的空间尺度是困难的，其高度的可变性，这是一个关键的挑战，N2O排放管理。在这里，静态室测量（n= 60）和土壤样品（n= 129），收集约每周一次的时间间隔（n= 6）为42天后立即在明尼苏达州南部玉米田（15.6公顷），典型的系统普遍在美国玉米带。这些数据被集成到一个地质统计模型，解决了一氧化二氮排放量在一个高的空间分辨率（1米）。现场规模的N2O排放表现出高度的空间变异性，并分为三类的排放强度：热点，中间，和冷点。热点地区的排放率是非热点地区的2倍。因此，36%的现场规模的排放可归因于热点，尽管只占总领域面积的21%。海拔的变化导致热点在可预测的位置发展，这是容易的地形集中造成的养分和水分积累。由于这些功能是相对静态的，我们的数据和分析表明，有针对性的热点管理可以有效地减少多达17%的现场规模的排放量，考虑到大气N2O的有害影响，一个显着的好处。
Anthropogenic emissions of nitrous oxide (N2O), a trace gas with severe environmental costs, are greatest from agricultural soils amended with nitrogen (N) fertilizer. However, accurate N2O emission estimates at fine spatial scales are made difficult by their high variability, which represents a critical challenge for the management of N2O emissions. Here, static chamber measurements (n= 60) and soil samples (n= 129) were collected at approximately weekly intervals (n= 6) for 42-d immediately following the application of N in a southern Minnesota cornfield (15.6-ha), typical of the systems prevalent throughout the U.S. Corn Belt. These data were integrated into a geostatistical model that resolved N2O emissions at a high spatial resolution (1-m). Field-scale N2O emissions exhibited a high degree of spatial variability, and were partitioned into three classes of emission strength: hotspots, intermediate, and coldspots. Rates of emission from hotspots were 2-fold greater than non-hotspot locations. Consequently, 36% of the field-scale emissions could be attributed to hotspots, despite representing only 21% of the total field area. Variations in elevation caused hotspots to develop in predictable locations, which were prone to nutrient and moisture accumulation caused by terrain focusing. Because these features are relatively static, our data and analyses indicate that targeted management of hotspots could efficiently reduce field-scale emissions by as much 17%, a significant benefit considering the deleterious effects of atmospheric N2O.