Wind tunnelIntegrated HorizontalFlux method

AGM & EC approaches

The Green Duo

0 10 20 30 40 50 60 70 80 90 1000

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

f(x) = 0.135845309734508 ln(x) + 0.638337851283387R² = 0.818966876397817

ug N/tube

Fetch (m)

Green DuoSlurry : Water =1 : 2(May 2012)

Year: 2012

Nienhuis & Lantinga (2012)

Two-dimensional NH3 concentration profiles (2014)

0 50 100 150 200 250 300 350 4000

60

120

180

240

300

360

Wind direction at 3.70 m height (anticipated fetch 75 degrees; average wind direction first 360 min = 73 degrees); distance 3 km (edge of

the village Winsum)

0 10 20 30 40 50 600

0.5

1

1.5

2

2.5

f(x) = 0.30995031976 ln(x) + 0.68022791001R² = 0.829225561860193

Broadcast; 20 cm

0 10 20 30 40 50 600

0.5

1

1.5

2

2.5

f(x) = 0.1188239775099 x^0.3459238860656R² = 0.873014916228128

Broadcast; 1 m

0 10 20 30 40 50 600

0.5

1

1.5

2

2.5

f(x) = 0.01409830961 ln(x) + 0.1129423715R² = 0.271358805297806

Broadcast; 5 m

0 10 20 30 40 50 600

0.5

1

1.5

2

2.5

f(x) = 0.0895480361726 ln(x) + 0.2652536039082R² = 0.68671569808227

Shallow injection; 20 cm

0 10 20 30 40 50 600

0.5

1

1.5

2

2.5

f(x) = 0.105841154865107 x^0.281123368290767R² = 0.672343106296746

Shallow injection; 1 m

0 10 20 30 40 50 600

0.5

1

1.5

2

2.5

f(x) = 0.0149369232107 ln(x) + 0.0951525760977R² = 0.395702731864831

Shallow injection; 5 m

0 10 20 30 40 50 600

0.5

1

1.5

2

2.5

f(x) = 0.0741599195896 ln(x) + 0.2061536493236R² = 0.571005198736628

Green Duo; 20 cm

0 10 20 30 40 50 600

0.5

1

1.5

2

2.5

f(x) = 0.091144079428201 x^0.206586067145448R² = 0.441420202359298

Green Duo; 1 m

0 10 20 30 40 50 600

0.5

1

1.5

2

2.5

f(x) = 0.010157402877 ln(x) + 0.0738030633R² = 0.515188380249629

Green Duo; 5 m

16.6 m3/ha 25.6 m3/ha 18.2 m3/ha

µg NH4-N/tube

Fetch (m)

OASIS EFFECT: curvilinear increase NH3 along the whole fetch at all heights

According to Itier & Perrier (1976), cited in Genermont & Cellier (1997), the real mean NH3 flux from a manured field due to the oasis effect is equivalent to the instantaneous flux at a distance of 30% of the total fetch.

This implies that when the IHF approach is applied between 25 and 50 m downwind, the calculated NH3 emission represents the NH3 emission from a practical grassland field with a fetch of 125 m (125 m x 0.3 = 37.5 m, i.e. just in between 25 and 50 m).

0 1 2 3 4 5 60

2

4

6

8

10

12

Fluxes at 7.5 m

Fluxes at 37.5 m

Kg NH3-N/ha.m

EF ~ 65% EF ~ 15%

Height (m)

Broadcast application 26 kg NH4-N/ha

Conclusions

- This experiment clearly demonstrates the effect of plot size on the measurement outcome: an overestimation of the NH3 emission in the order of a factor 4 for practical grassland fields due to the oasis effect when using the IHF method in the way as has been been applied in The Netherlands since the early 1990s (manured circles with only a radius of 25 m, i.e. a representative calculation distance of only 25 m x 0.3 = 7.5 m from the windward edge).

- Whole-field ammonia Emission Factors (sunny conditions + wind):Surface applied (broadcasted) 15%Sward injection (undeep) 4%Green Duo (broadcasted + water spray) 4%

Output FIDES Model (May 2015; M. Carozzi):- Patterns of simulated NH3 concentrations above applied slurry- Two heights: 25 cm and 5 m- Averaged (weighted for wind speed differences) over three heights (also 1 m):

difference IHF emission between 0-25 m and 25-50 m (normalized horizontal flux): about a factor 7 !!!

Loubet et al. (2010): ... When the fetch is small, the oasis effect is maximal, and the emission decreases sharply with distance.

!!!!!!!

!!!!!!!

Model: non-rectangular hyperbola

B: initial slope

D

C

A: curvature (0 - 1)

Green Duo

Diffusive component total NH3 emission: only 1- 2 % !!!

NH3 emission from applied slurry: > 90% within first 6 hours

Three-dimensional characterization of the ammonia plume from a beef cattle feedlot (17,220 head)

Ralf M. Staebler et al. (Atm. Environm., 2009)

Conclusion: within a distance of 4 km from the farm more than 50% of the emitted NH3 has reached a vertical height of more than 135 m

Source: Leith, Scotland

Detectable NH3 compensation point of grasses : > 10 ug/m3

Biomonitors: summer barley plants in low N-solution (according to method of S. Sommer)Warning: denitrification losses of added mineral fertiliser-N (3 expts: losses 16-21 % -> Calculations based on 14N / 15N ratio’s lead too great overestimations of NH3 deposition)

0 200 400 600 800 1000 1200 14000

5

10

15

20

25

30

35

0

20

40

60

80

100

120

140

160

180

200

220

240

260

Mts. Duiven (west of Dwingelderveld): 600 dairy cows (zero grazing)

Distance to source (m)

NH3

[µg

m3]

kg--1

ha-

1 yr

-1

Dry deposition measured with biomonitors

Dry deposition OPS model including “background deposition”

Calculated NH3 concentrationwith OPS model

Dry deposition OPS model vs. measurements (spring –early summer 2011):

- Underestimation around livestock barns (< 300 m)

- Overestimation further away from the barns (> 400 m: undetectable measured dry deposition)

Spring – early summer 2012(83 days): g N / pot

Site 1 (mean 83 days): 10.4 µg NH3 m-3 (source: RIVM)

1

12

2

3

3

4

4 5 Lichens (H. van Dobben, Alterra) [NH3] : 2 > 3 = 1 > 4 > 5Biomonitors: [NH3] : 2 > 1,3,4,5→ Compensation point > 10 µg NH3 m-3

5

1985 1990 1995 2000 2005 2010 20150

100

200

300

400

500

600

700

800

900

1000

No effect slurry injection (1990-1998)

MINAS (1998-2006): 30% decrease (30% less manure-N excretion Dutch livestock sector)

Nitrate Directives since 2006:10% decrease

0 20 40 60 80 100 120 1400

0.5

1

1.5

2

2.5

Slurry applied 0-65 m; wind 7 m/s; median values (n=10; ug N/tube)

25 cm Polynomial (25 cm) 100 cmPolynomial (100 cm) 400 cm Polynomial (400 cm)

<---------------------------slurry---------------------------->

60 70 80 90 100 110 120 1300.00

0.50

1.00

1.50

2.00

2.50ug N/tube

<---------------------slurry-------------->