1. Quantifying in situ N2 fluxes from an intensively managed calcareous soil using the 15N gas-flux method
- Author
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Yan LIU, Rui WANG, Zhan-lei PAN, Xun-hua ZHENG, Huan-huan WEI, Hong-rui ZHANG, Bao-ling MEI, Zhi QUAN, Yun-ting FANG, and Xiao-tang JU
- Subjects
N2 fluxes ,15N gas-flux method ,N2O/(N2O+N2) ratios ,detection limit ,intensive cropping system ,Agriculture (General) ,S1-972 - Abstract
Denitrification-induced nitrogen (N) losses from croplands may be greatly increased by intensive fertilization. However, the accurate quantification of these losses is still challenging due to insufficient available in situ measurements of soil dinitrogen (N2) emissions. We carried out two one-week experiments in a maize–wheat cropping system with calcareous soil using the 15N gas-flux (15NGF) method to measure in situ N2 fluxes following urea application. Applications of 15N-labeled urea (99 atom%, 130–150 kg N ha−1) were followed by irrigation on the 1st, 3rd, and 5th days after fertilization (DAF 1, 3, and 5, respectively). The detection limits of the soil N2 fluxes were 163–1 565, 81–485, and 54–281 μg N m−2 h−1 for the two-, four-, and six-hour static chamber enclosures, respectively. The N2 fluxes measured in 120 cases varied between 159 and 2 943 (811 on average) μg N m−2 h−1, which were higher than the detection limits, with the exception of only two cases. The N2 fluxes at DAF 3 were significantly higher (by nearly 80% (P
- Published
- 2022
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