Nitrogen Input Control on Danish farms
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Transcript of Nitrogen Input Control on Danish farms
Danish Agricultural Advisory ServiceNational Centre
Nitrogen Input Control on Danish farms
Senioradviser Leif Knudsen
Danish Agricultural Advisory Service
Danish Agricultural Advisory ServiceNational Centre
Outline:
• Background for regulation of nitrogen input• Review of the legislation• The current legislation• The effect of the legislation on farmers’
practice• The economic consequences for the
farmers• The effect on environmental parameters
Danish Agricultural Advisory ServiceNational Centre
Two main problems caused by leaching of nitrogen from agriculture:
• Increase of nitrate in ground water /drinking water• Incidences of depletion of nitrogen in the marine water (inlets, eustaries)
Danish Agricultural Advisory ServiceNational Centre
mineral
fertilizer,kg/ha
mg nitrate pr.
liter
Fertiliser
Fertiliser
Nitrate
Depletion of oxygen has always occured. Depletion of oxygen is more common with high N and P content. Depletion of oxygen was more common in the 80’ies and 90’ies than before.
Eutrofication in inlets Cover on buttom after an incident of lack of oxygen
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Time Plan Significant elements in legislation:
1985 NPO-plan -regulation of allowed animal unit per ha.
- min. storage capacity for animal manure
1987 Water
Environm.
Plan I
-50 pct reduction in N-leaching from agr.-65 pct ”autumngreen fields”-Slurry in autumn only to wintercovered fields
1992 Sustain-able agri-culture
-Slurry only to grass or oilseed rape in autumn-Max. N-standards for crops (N-quota per farm) -Min. utilization of nitrogen in animal manure-Fertilizer plans and -accounts.
1998 Water
Environm.
Plan II
-10 pct decrease of N-standards (The N-quota)- 6 percent ”super” green fields in autumn-15 pct higher utilization of N in animal manure
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Maximum allowed animals per hectare
Animal Category Animal unit per ha
Number of animals per ha
Dairy cows *1 1,7/2,3 1,4/2,0
Sows 1,4 6,0
Piglets 7,5-30 kg 1,4 245
Pigs, 30-102 kg 1,4 50
Hens 1,4 289
Chickens 1,4 4930
*1 without heifers1 Animal Unít = 100 kg N ab storage
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Storage capacity for animal manure
Normal: At least 9 months on pig farms.7 months on dairy farms with animals gra-zing in summerNew stables: farmers normally invest for 12 months storage capacity
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Animal manure continued
Cover of liquid
manure:
Natural crust is enough but control is intensified by the authorities. If not in order there must be a solid cover (e.g. concrete, tent)
Spreading time
From harvest to 1st of February spreading of liquid manure is banned except: -on winter oilseed rape from harvest to 1 st of October-on grassland (overwintering) until 1 st October -On grass for seed until 15. October
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Animal manure continued:
Spreading technique:
Use of broadcasting is banned. All liquid manure must be spread with trailinghoses or direct injection
Manure spread on bare soil mustbe incorporated within 6 hours
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Covercrops:
65 percent of the area must be ”Autumn Green fields: Wintercereal, winteroilseedrape, beets, potatoes(late), corn…
6 percent of the area must be ”supergreen Fields: catchcrops of undersown grass or crusifer crops.
Danish Agricultural Advisory ServiceNational Centre
Nitrogen quotas per farm:
Nitrogen quota for each crop+/- Correction for yearly N-prognosis- Effect of catchcrops from last year- Minimum utilization of animal
manure= Nitrogen quota in mineral fertiliser
for the farm
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Coarse sand Loam(15-25 percent clay)
Crop Yield
tonnes/ha
Kg N/ha
Yield
tonnes/ha
Kg N/ha
Winterwheat after cereals 5,0 154 8,5 171
Winterwheat after wi.rape 5,6 124 9,3 155
Spring barley after cereal 4,0 118 6,1 128
Spring barley after clovergrass
4,4 58 6,7 68
Examples of Danish N-quotas for different crops
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Minimum demands for utilization of total
N in manure, %
Pig slurry 75
Cattle slurry 70
Solid manure + urine 65
Deep litter 45
Sewage sludge 45
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Example of a quota for a pig farmer50 ha Winterwheat after
cereals167 kg N/ha 8350
25 ha Spring Barley 104 kg N/ha 2600
25 ha Sugar Beet 107 kg N/ha 2675
100 ha Total N-quota for the crops 13625
5000 pigs produced with 26,7 kg N per 10 prod.
13.350 kg N produced in total x 75 pct. utilization
10013
Total N-quota left for N in mineral fertiliser 3613
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0
50
100
150
200
250
300
350
400
450
1980 1985 1990 1995 2000 2005
Th
ou
s. t
on
Nit
rog
enMineral N
N in animal manure
Danish Agricultural Advisory ServiceNational Centre
0
100
200
300
400
500
600
190
0
192
5
195
0
197
5
200
0
100
0 t
on
s N
Nitrogen surplus in Danish agriculture
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Time for application of organic manure
Slurry
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Winter crop coverage
Danish Agricultural Advisory ServiceNational Centre
0
50
100
150
200
250
300
350
400
450
500
1985 1990 1996 1997 1998 1999
1000
to
n N
Misc.
Change in soil content
N-evaporation
Denitrificatron
Leaching
N surplus in fields in DK
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Development in N-concentration1990/91 – 1998/99
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Modelling of N-leachingin 7 catchments
N-l
eac
hin
g a
t st
and
ard
pre
cip
ixa
tio
n
Danish Agricultural Advisory ServiceNational Centre
Review of the legislationYear and action Regulation:
1985: NPO Storage capacity, Max. allowed animal per ha.
1987: WEPP I 65 pct. Wintercovered fields, storage capacity
1992:Sustainable Agriculture
Max. N-quotas, banned autum applied liquid manure, fertiliser accounts. Minimum utilization of animal manure
1998: WEPP II 10 percent reduction of N-quotas, 6 pct. additional catch crops
2004: WEPP III ????
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Nitrogen and phosphorus in artificial fertiliser 1990-2002
0
20
40
60
80
100
120
Denm
ark
Sweden
Finla
nd
Germ
any
Holland
Belgiu
m-L
ux.
Great
Brit
ain
Irela
nd
France
Austria
Italy
Spain
Portugal
Greec
e EURel
. d
evel
op
men
t 19
89 t
o 2
002
Nitrogen
Phosphorus
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Phosphorus surplus
-100
102030405060708090
190
0
192
5
195
0
197
5
200
0
1000
to
ns
P