Knowledge Management System of Northwest Institute of Plateau Biology, CAS
Year-round measurements of nitrous oxide emissions and direct emission factors in extensively managed croplands under an alpine climate | |
Liu, Chunyan; Hu, Xiaoxia; Zhang, Wei; Zheng, Xunhua; Wang, Rui; Yao, Zhisheng; Cao, Guangmin | |
2019 | |
发表期刊 | AGRICULTURAL AND FOREST METEOROLOGY |
卷号 | 274 |
摘要 | Estimates of China's agricultural nitrous oxide (N2O) emission inventory are mainly based on data for intensively managed croplands in the monsoon zone. Observations of N2O fluxes and direct emission factors (EF(d)s) remain limited in the non-monsoon zone in China. In this study, year-round measurements of yields, meteorological and soil environmental factors, and N2O fluxes were conducted in highland barley (HB, with the application of synthetic fertilizers) and oilseed rape (OR, with the mixed application of air-dried sheep manure and synthetic fertilizers) cropping systems with typical extensive management in the Qinghai-Tibetan Plateau. The cumulative N2O emissions during the freeze-thaw period (0.10 and 0.31 kg N ha(-1)) and annual scale (0.35 and 0.70 kg N ha(-1) yr(-1) in the HB and OR fields, respectively) were in the low range of globally reported freeze-thaw emissions from seasonally frozen croplands. The annual EF(d)s were 0.19% +/- 0.11% and 0.04% +/- 0.14% in the HB and OR fields, respectively, which were much lower than the national average and IPCC default values. The extensive management (low fertilization rates, aboveground plant nitrogen removal, and rain-fed agriculture) and alpine climate led to low emissions and EF(d)s in the croplands of the Qinghai-Tibetan Plateau. Although the annual N2O emissions and EF(d)s were relatively low, extensive management still needs to be optimized to maintain the sustainability of agricultural production on the plateau because of the extremely low nitrogen use efficiencies (crop recovery efficiency of applied nitrogen: 0.2 kg N kg(-1) N) and negative nitrogen surpluses (-58.7 and -8.0 kg N ha(-1) yr(-1) in the HB and OR fields, respectively). To reduce the uncertainty in the estimates of global and national emission inventories, more studies should be conducted in the non-monsoon zone owing to the peculiarity of management strategy and climate, and the dramatic expansion of cropland area. |
关键词 | Soil freeze-thaw Nitrogen use efficiency Nitrogen surplus Highland barley Oilseed rape Qinghai-Tibetan Plateau |
文献类型 | 期刊论文 |
条目标识符 | http://210.75.249.4/handle/363003/59722 |
专题 | 中国科学院西北高原生物研究所 |
推荐引用方式 GB/T 7714 | Liu, Chunyan,Hu, Xiaoxia,Zhang, Wei,et al. Year-round measurements of nitrous oxide emissions and direct emission factors in extensively managed croplands under an alpine climate[J]. AGRICULTURAL AND FOREST METEOROLOGY,2019,274. |
APA | Liu, Chunyan.,Hu, Xiaoxia.,Zhang, Wei.,Zheng, Xunhua.,Wang, Rui.,...&Cao, Guangmin.(2019).Year-round measurements of nitrous oxide emissions and direct emission factors in extensively managed croplands under an alpine climate.AGRICULTURAL AND FOREST METEOROLOGY,274. |
MLA | Liu, Chunyan,et al."Year-round measurements of nitrous oxide emissions and direct emission factors in extensively managed croplands under an alpine climate".AGRICULTURAL AND FOREST METEOROLOGY 274(2019). |
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