Figure 4. Isotopic fingerprints and emissions of N₂O.

(a), δ¹⁸O. (b), δ¹⁵N^bulk. (c), δ¹⁵N site preference (SP). (d), δ¹⁸O (vs. SMOW) versus SP. (e), δ¹⁸O versus δ¹⁵N^bulk. (f), cumulative N₂O emissions. AS, CN, CN + C, and CK denote amendment with ammonium sulfate, calcium nitrate, and calcium nitrate + glucose + compaction of soil, and control, respectively. Error bars in plots (a), (b), (c), and (f) are standard deviation of the mean (n = 4). Note that data points are individual observations of the treatments in plots (d) and (e).