Table 3. C 1s and N 1s bonding state and their relative atomic percentage on the biochar surfaces of eucalypt biochar before addition to columns, extracted from the soil LMH5% treatments and from the 100% biochar treatment, as determined by XPS (regional scan).

Unincubated biochar				Biochar from LMH5% soils		BC100% after addition of N2O
Name	Functional Groups	Peak BE(mV)	At. %	Peak BE(mV)	At. %	Functional Groups	Peak BE(mV)	At. %
C1s A	C = C/C-C/C-H	284.47	68.24	284.38	35.68	C = C/C-C/C-H	284.57	57.10
C1s B	C-O	286.57	6.76			C-O	286.56	12.11
C1s C	C = O	287.97	2.40	286.48	8.04	C = O	287.96	3.35
C1s D	O = C-O	289.17	0.53	287.88	2.89	O = C-O	289.16	3.65
C1s E	Shake up peaks	290.36	6.70	289.08	2.74
C1s F						Shake up peaks	290.87	4.23
	Carbonate			291.21	1.21
N1s A	-O-C = N/pyridine pyrrole/NH3	400.42	0.40	400.47	0.77		400.93	0.49
N1s B	NH4/NH2 groups	398.55	0.28	398.69	0.13		399.23	0.25
N1s C	Pyridine/N-O/Chemisorbed NH3			402.56	0.11