A slow release nitrogen fertiliser produced by simultaneous granulation and superheated steam drying of urea with brown coal

Chemical and Biological Technologies in Agriculture

Table 6 Cumulative emissions of N₂O-N (µg per column) from the surface of the soil columns over the duration of the experiment

Treatment	Cumulative N₂O-N (µg) emissions at 21 d^a	Cumulative N₂O-N (µg) emissions at 42 d^a
U	28 ± 13 a	129 ± 20 a
UBC-H	33 ± 8 a	145 ± 36 a
UBC-L	11 ± 4 b	76 ± 9 b
BC	0.4 ± 0.1 c	1.9 ± 0.3 c
Control	1.4 ± 2.2 c	1.6 ± 2.2 c

Treatment abbreviations are: U urea; UBC-H urea-brown coal granule (17 % N); UBC-L urea-brown coal granule (8.7 % N); BC brown coal granule; control no N or C addition
^a Errors are 95 % confidence levels. Within a column, letters adjacent to values are different if the values within a column are significantly different (P < 0.05)