Global estimates of gaseous emissions of NH3, NO and N2O from agricultural land

N application rate (kg/ha)	0	1-50	50-100	100-150	150-200	200-250	>250
No. observations	206	33	184	113	98	56	156
Mean	1.1	1.6	1.5	1.9	2.4	3.3	6.8
Median	0.6	1.2	0.7	1.2	1.2	1.4	4.1
Balanced mean	0.5	1.8	1.8	2.0	2.3	3.1	5.4
Balanced median	0.5	1.0	1.0	1.2	1.4	1.9	3.5
Climate type	Clim1	Clim2	Clim3	Clim4	Clim5	Clim6	Clim7	Clim8
No. observations	253	389	50	61	77	8	6	2
Mean	2.2	2.5	4.2	5.7	2.1	0.2	1.2	4.0
Median	1.0	1.3	0.8	1.8	0.9	0.2	1.1	4.0
Balanced mean	1.8	1.2	4.3	4.5	1.8	0.6	2.4	3.5
Balanced median	0.9	0.8	2.0	1.7	1.3	0.5	0.7	1.2
Soil organic C content (%)	<1.0	1.0-3.0	3.0-6.0	>6
No. observations	92	353	126	18
Mean	1.3	2.0	2.7	5.0
Median	0.8	1.0	1.5	1.6
Balanced mean	2.0	1.6	2.1	4.4
Balanced median	0.8	0.7	1.1	1.8
Soil N content (%)	<0.05	0.05-0.15	0.15-0.3	>0.3
No. observations	2	71	228	29
Mean	3.0	1.6	2.3	4.2
Median	3.0	1.0	1.2	2.3
Balanced mean	2.3	2.2	3.3	2.3
Balanced median	0.7	1.0	1.4	1.2
Soil texture class	Coarse	Medium	Fine	Soil drainage	Poor	Good
No. observations	447	147	134	No. observations	193	460
Mean	2.8	2.6	1.9	Mean	2.8	2.6
Median	1.2	1.3	0.9	Median	1.4	1.1
Balanced mean	2.3	2.1	3.1	Balanced mean	2.6	2.4
Balanced median	1.2	0.8	1.3	Balanced median	1.2	0.9
Soil pH	<5.5	5.5-7.3	>7.3
No. observations	93	359	109
Mean	2.8	2.3	2.0
Median	1.0	1.1	0.7
Balanced mean	2.9	3.3	1.3
Balanced median	1.2	1.2	0.8
Fertilizer type	AA	AF	AN	CAN	NF	Mix
No. observations	38	59	117	61	53	25
Mean	4.4	0.6	3.0	2.3	2.6	3.4
Median	2.7	0.4	1.4	1.7	0.7	2.2
Balanced mean	4.9	1.9	3.2	2.0	2.5	3.3
Balanced median	1.4	1.1	1.2	1.0	0.7	1.8
Fertilizer type	NP	O	OS	UUR	UAN
No. observations	16	74	41	98	37
Mean	3.8	4.7	5.9	1.9	3.2
Median	3.0	1.0	4.2	0.7	2.7
Balanced mean	1.7	3.1	3.5	2.2	3.3
Balanced median	0.7	1.2	1.4	1.2	0.9
Fertilizer application mode	b	bpi	i	s
No. observations	163	4	162	122
Mean	3.4	0.8	2.7	2.4
Median	1.3	0.7	1.2	1.4
Balanced mean	2.8	2.6	2.7	2.3
Balanced median	1.3	1.0	1.2	1.0
Timing of application	Single	Single/ps	Split
No. observations	337	153	104
Mean	2.5	4.2	3.3
Median	1.0	2.2	1.6
Balanced mean	3.0	2.1	2.4
Balanced median	1.2	1.2	1.5
Crop type	Grass	Grass+ clover	Legume	Rice	Other
No. observations	177	16	36	61	512
Mean	3.3	1.1	1.3	0.7	2.9
Median	1.4	0.9	1.1	0.5	1.3
Balanced mean	2.7	1.2	3.6	1.9	3.2
Balanced median	1.0	0.8	2.9	0.3	2.1
Measurement technique	c	co	g	m	cfd
No. observations	766	15	7	32	25
Mean	2.5	1.7	4.5	1.7	8.8
Median	1.1	1.2	3.6	1.3	3.3
Balanced mean	2.7	1.5	2.1	2.8	4.1
Balanced median	0.9	0.7	2.6	1.1	0.8
Experiment length	<120	120-180	180-240	240-300	>300(days)
No. observations	343	132	42	34	277
Mean	1.4	2.3	2.1	2.6	4.5
Median	0.5	1.2	1.2	1.3	2.3
Balanced mean	2.0	1.9	2.1	2.4	4.2
Balanced median	0.7	0.7	1.1	1.2	1.9
Measurement	>1m./d	1m./d	1m./2-3 d	1m./3-7 d	<1m./wfrequency ¹
No. observations	140	286	78	262	46
Mean	1.5	2.9	2.6	2.8	4.5
Median	0.8	1.1	1.1	1.3	2.0
Balanced mean	2.1	3.1	3.1	3.2	2.7
Balanced median	1.0	0.9	1.9	1.3	1.4

Reprinted from Bouwman et al., 2001b 1. For the classes of measurements frequency of one or more than one per day, generally these high frequencies are used in periods following fertilizer application or rainfall events, with lower frequencies in periods with low emission rates.

N application rate (kg/ha)	0.0	1-100	100-200	>200
No. observations	21	45	16	17
Mean	0.3	0.5	0.5	5.4
Median	0.1	0.1	0.6	2.8
Balanced mean	1.7	2.4	2.5	4.3
Balanced median	0.2	0.8	1.0	1.7
Climate type	Clim1	Clim2	Clim3	Clim4	Clim5	Clim6	Clim7	Clim8
No. observations	19	34	18	0	18	10	0	0
Mean	1.1	1.1	1.0	-	2.7	0.1	-	-
Median	0.6	0.1	0.6	-	0.8	0.1	-	-
Balanced mean	-3.5	1.8	1.9	-	0.4	1.2	-	-
Balanced median	0.3	0.4	1.6	-	0.3	0.9	-	-
Soil organic C	<3.0	>3.0content (%)
No. observations	47	8
Mean	0.5	4.5
Median	0.1	0.4
Balanced mean	0.2	0.5
Balanced median	0.3	1.3
Soil Texture class	Coarse	Medium	Fine
No. observations	71	13	5
Mean	1.5	0.4	0.0
Median	0.2	0.2	0.0
Balanced mean	0.3	0.4	0.4
Balanced median	1.1	0.4	0.4
Soil drainage	Poor	Well
No. observations	7	60
Mean	0.5	1.8
Median	0.5	0.4
Balanced mean	-0.4	1.1
Balanced median	0.4	0.8
Soil pH	<5.5	>5.5
No. observations	23	53
Mean	1.7	0.3
Median	0.1	0.1
Balanced mean	0.6	0.1
Balanced median	0.8	0.4
Fertilizer type	AA	AF	AN	CAN	NF	Mix
No. observations	2	14	17	5	15	1
Mean	16.3	1.1	1.7	0.5	0.5	6.3
Median	16.3	0.2	0.4	0.4	0.1	6.3
Balanced mean	1.1	0.3	-0.2	-1.1	0.1	4.3
Balanced median	0.5	0.4	0.6	0.2	0.5	2.0
Fertilizer type	NP	O	OS	UUR	UAN
No. observations	0	3	0	19	1
Mean	-	0.6	-	1.3	1.0
Median	-	0.5	-	0.0	1.0
Balanced mean	-	-0.4	-	0.7	-0.5
Balanced median	-	0.2	-	0.5	4.2
Fertilizer application mode	b	bpi	i	s
No. observations	27	0	8	33
Mean	1.1	-	5.5	0.1
Median	0.8	-	0.4	0.0
Balanced mean	1.4	-	-1.1	-0.3
Balanced median	1.0	-	0.2	0.5
Timing of application	Single	Single/ps	Split
No. observations	28	3	6
Mean	1.7	3.1	0.7
Median	0.1	2.7	0.8
Balanced mean	1.8	-0.8	-1.3
Balanced median	0.5	1.0	0.5
Crop type	Grass	Grass-clover	Legume	Rice	Other
No. observations	23	0	16	2	51
Mean	1.9	-	0.7	1.4	1.3
Median	0.7	-	0.1	1.4	0.1
Balanced mean	1.0	-	1.7	-3.5	2.3
Balanced median	0.6	-	0.4	0.4	1.1
Measurement technique	c	cfd
No. observations	30	69
Mean	0.5	1.6
Median	0.5	0.1
Balanced mean	0.3	0.4
Balanced median	0.5	0.6
Length of experiment	<120	>120(days)
No. observations	64	35
Mean	0.4	3.0
Median	0.1	0.8
Balanced mean	-1.2	1.9
Balanced median	0.3	1.1
Measurement	>1m./d	1m./d	1m./2-3 d	1m./3-7 d	<1m./wfrequency ¹
No. observations	51	20	8	10	2
Mean	0.2	2.9	4.6	0.9	0.7
Median	0.1	1.1	0.4	0.7	0.7
Balanced mean	-1.0	1.2	7.1	-2.0	-1.6
Balanced median	0.2	1.0	1.0	0.9	1.2

Reprinted from Bouwman et al., 2001b 1. For the classes of measurements frequency of one or more than one per day, generally these high frequencies are used in periods following fertilizer application or rainfall events, with lower frequencies in periods with low emission rates.

Annex 2 Tables

Annex 2
Tables