Upload
bruno
View
23
Download
0
Embed Size (px)
DESCRIPTION
How to half N-losses, improve N-efficiencies and maintain yields? The Danish Case. - PowerPoint PPT Presentation
Citation preview
DIAS
How to half N-losses, improve N-efficiencies and maintain yields? The Danish Case
By Tommy Dalgaard ([email protected]), C.D. Børgesen, J.F. Hansen, N.J. Hutchings, U. Jørgensen and A. Kyllingsbæk.
Danish Institute of Agricultural Sciences. Department of Agroecology.
Plantekongres 2006. Session T96: Tools for reducing N-losses. Can we fulfil the WFD?
DIAS
Programme
• Agriculture & Environmental problems __in Denmark
• Developments in the N balance
• N-yields versus N-losses
• Catalogue of statutory measures to __ improve N-management
_- How half N-losses and maintain yields?
DIAS
Intensive agriculture in Denmark
• 2,7 mio ha agricultural land (63% of total area)
• 5 mio people - 4,5 mio t milk - 24 mio pigs/yr
• 8 t milk/cow/yr
• 24 piglets/sow/yr
•7,5 t wheat/ha/yr
• 7500 km coastline
• Drinking water = groundwater
DIAS
Dairy Cows Pigs Wheat (1000’s) (1000’s) (1000 ha)
DIAS
The nitrogen balance
DIAS
Development phases
N-imports N-exports
0
20
40
60
80
100
120
140
160
180
200
1900 1920 1940 1960 1980 2000
year
index
N-fertiliser import
Fodder import
From the atmosphere
-50
0
50
100
150
200
1900 1920 1940 1960 1980 2000
year
index
Vegetable exports Animal exports
NB: year 2000= index 100
DIAS
I: Traditional livestock farming (1900-1950)
0
20
40
60
80
100
120
140
160
180
200
1900 1920 1940 1960 1980 2000
year
index
N-fertiliser import
Fodder import
From the atmosphere
-50
0
50
100
150
200
1900 1920 1940 1960 1980 2000
year
index
Vegetable exports Animal exports
NB: year 2000= index 100
I I
DIAS
II: The green revolution (1950-1983)
0
20
40
60
80
100
120
140
160
180
200
1900 1920 1940 1960 1980 2000
year
index
N-fertiliser import
Fodder import
From the atmosphere
-50
0
50
100
150
200
1900 1920 1940 1960 1980 2000
year
index
Vegetable exports Animal exports
NB: year 2000= index 100
I II I II
DIAS
III: Sustainable development (1984-?)
0
20
40
60
80
100
120
140
160
180
200
1900 1920 1940 1960 1980 2000
year
index
N-fertiliser import
Fodder import
From the atmosphere
-50
0
50
100
150
200
1900 1920 1940 1960 1980 2000
year
index
Vegetable exports Animal exports
NB: year 2000= index 100
I II III I II III
DIAS
N-exports and crop yields
DIAS
N-surplus, N-leaching and N-efficiency
DIAS
Distribution of simulated N-leaching
DIAS
Action plans to reduce N-losses
• 1985: Action plan to reduce N- and P-pollution
• 1987: First action plan for the aquatic environment (AP-I)
(Aim: half N-losses and reduce P-losses by 80%)
• 1991: Action plan for sustainable agriculture
• 1998: Second Action Plan (AP-II)
• 2000: AP-II midterm evaluation and enforcement
• 2001: Ammonia Action Plan
• 2004: Third Action Plan (AP-III)
DIAS
The 1985 Action Plan
Max. stock density of 2 LU ha-1 (1 LU corresponds to one large dairy cow or 30 porkers produced)
Minimum 6 months slurry storage capacity Ban on slurry spreading between harvest and
Oct 15 on soil destined for spring cropping Various measures to reduce runoff from silage
clamps and manure heaps Mandatory floating barriers on slurry tanks
DIAS
AP-I for the Aquatic Environment
Min. 9 months slurry storage capacity Mandatory fertiliser and crop rotation plans Minimum proportion of area to be planted with
winter crops Mandatory incorporation of manure within 12
hours of spreading
DIAS
Action Plan for Sust. Agriculture
Ban on slurry spreading from harvest until 1 Feb., except on grass and winter rape
Maximum limits on the plant-available N applied to different crops, equal to the economic optimum
Statutory norms for the proportion of manure N assumed to be plant-available
DIAS
AP-II for the Aquatic Environment
Enforced statutory manure N-norms Max application of N to crops reduced to 10% below
the economic optimum Red. of max. stock density to 1.7 LU ha-1 6% of the rotational area to be planted with catch crops. N retained by catch crops must be incl. in fertiliser plans Expectation that animal feeding practice will be
improved to reduce N excretion Subsidies to convert to organic farming Subsidies to establish wetlands Subsidies to reduced N inputs in sensitive areas Subsidies to afforestation
DIAS
Ammonia Action Plan
DIAS
AP-III for the Aquatic Environment
Enforced statutory manure N-norms Improved utilisation of N and P in feed A tax of DKK 4 kg-1. mineral P in feed Establishment of buffer zones along streams and around
lakes to reduce discharge of P Protection zones of 300 m around ammonia sensitive
habitats Request for more catch crops Strengthening of organic farming regulations Further wetland areas Further afforestation
DIAS
Summary
Improved N-management via:
• Mandatory fertilisation accounts
• Norms for fertilisation of crops
• Subsidies for new manure equipment and __environmental friedly practices
• Extensive research, demonstration and __ advisory programmes
• Better utilisation of manures
DIAS
Norms for manure N-utilisation
% plant available N in manures
DIAS
Conclusion
The regulations have been succesfull and might serve as inspiration for other countries
• N-leaching almost halved from 1985-2004
• Livestock production increased by 30%
• N crop yields sustained
Still posibilities and environmental needs for improvements.
Better methods for regionalised assessments needed for the implementation of the WFD