A Review of Chamber and Micrometeorological Methods to Quantify NH₃ Emissions from Fertilisers Field Application

Table 4

Comparison of ammonia cumulative emission in kg N ha⁻¹ and % applied N determined by different measurement methods.

Ammonia cumulative emission kg·N·ha^−1 (% applied N)			Source type	Reference crop	Important findings	Reference
Micrometeorological methods		Chambers methods
49.1^f(24.55%)^f		30.2^h (15.1%)^h	Exp 1 (1 m·s^−1); 200 kg·Urea-N·ha^−1	Cut sward	Rain leads to overestimating the NH3 losses with the wind tunnel.	Ryden et al. [87]
96.9^f(48.45%)^f		101^h (50.5%)^h	Exp 2 (1–3 m·s^−1); 200 kg Urea-N·ha^−1		Wind tunnel efficiency could enhance with automatic control of airspeed inside the tunnel, according to ambient wind speed.
10.8^f(41.7%)^f, +		10.7^g (41.4%)^g	Pig and cattle slurry; 24 kg TAN·ha^−1	Bare soil	Good accordance in the results between both methods under standard conditions in field applications.	Mannheim et al. [88]
15.6^f(77.4%)^f, +		15.2^g (74.4%)^g	12.3 kg TAN·ha^−1
3.4^f(27.2%)^f,+		4.3^g (35.2%)^g	20.4 kg TAN·ha^−1
1.9^f(7.3%)^f, +		11.2^g (42.1%)^g	26.6 kg TAN·ha^−1
(75%)^a,^∗		(71%)^h	Cattle slurry: 127.25 kg·N·ha^−1	Bare soil	Wind tunnels are preferred to make small plot comparative studies.	Misselbrook et al. [89]
(54%)^a,^∗		(21%)^h	Poultry manure: 613.74 kg·N·ha^−1
(29%)^a,^∗		(39%)^h	Poultry wetted manure: 316.2 kg·N·ha^−1
32.7^a(43.6%)^a	45.6^c (60.8%)^c	26.8–30.6^d (35.5%)^d	75 kg Urea-N·ha^−1	Bare soil	IHF(GT) tends to underestimate or overestimate ammonia flux (12.5 to 64%), while dynamic chambers and IHF(L) have a similar ammonia loss kinetic.	Pacholski et al. [58]
21.6^a(1.8%)^a	8.2^c (4.1%)^c	22.2^d (11.1%)^d	200 kg Urea-N ha^−1
23.9^a(19.9%)^a	21^c (17.5%)^c	25–29.8^d (20.8%)^d	120 kg Urea-N ha^−1
18.8^a(12.5%)^a	8.6^c (5.7%)^c	51–59.8^d (34%)^d	150 kg Urea-N ha^−1
9.9 (4.9%)^b		7.4 (3.7%)^m	Urea: 200 kg·N·ha^−1	Bare soil	WT measurements are affected by frequent sampling activities, but that correlation between WT and IHF method could be improved with 3 h of minimum sampler exposition time.	Scotto di Perta et al. [14]
46.8 (11.7%)^b		26.5 (6.63%)^m	Buffalo slurry: 400 kg·N·ha^−1
49.2 (27.95%)^b		26.4 (15%)^m	Buffalo digestate: 176 kg·N·ha^−1

Notes. Data in round brackets “( )”are expressed in % applied N. IHF = integrated horizontal flux; IHF(GT) = integrated horizontal flux with glass tubes, IHF(L) = integrated horizontal flux with Leuning et al.’s samplers, DTM = Dräger tube method; WT = wind tunnel; TAN = total ammoniacal-N; UAN = uric acid and ammoniacal-N. ^aIHF method by Leuning et al. [81]; ^bIHF method by Wood et al. [84]; ^cIHF method by Schjoerring et al. [82]; ^dDTM; ^eZINST; ^fIHF method by Denmean [90]; ^gWT by Braschkat et al. [62]; ^hWT by Lockyer [61]; ^mWT by Jiang et al. [64]. ⁺As % of applied TAN; as % of applied of UAN.