Danish Agricultural Advisory Service National Centre Nitrogen Input Control on Danish farms...

Danish Agricultural Advisory ServiceNational Centre

Nitrogen Input Control on Danish farms

Senioradviser Leif Knudsen

Danish Agricultural Advisory Service


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


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)


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


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


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


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


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


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


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.


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


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


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


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


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


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


Time for application of organic manure

Slurry


Winter crop coverage


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


Development in N-concentration1990/91 – 1998/99


Modelling of N-leachingin 7 catchments

N-l

eac

hin

g a

t st

and

ard

pre

cip

ixa

tio

n


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 ????


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


Phosphorus surplus

-100

102030405060708090

190

0

192

5

195

0

197

5

200

0

1000

to

ns

P

Danish Agricultural Advisory Service National Centre Nitrogen Input Control on Danish farms...

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