Date post: | 25-May-2015 |
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DAIRY FARM SYSTEMS FOR GOOD ECONOMIC AND
ENVIRONMENTAL PERFORMANCE
VICKI BURGGRAAF1
IRIS VOGELER1
PIERRE BEUKES2
DAVE CLARK2
1 AGRESEARCH LTD 2 DAIRYNZ
NEW ZEALAND $$$$
How can we farm profitably with a low environmental footprint?
48% NZ GREENHOUSE GAS
OVERVIEW
Model dairy farm with increased efficiency
1. Dairy intensification in NZ2. Causes of environmental issues3. Strategies to reduce negative impacts4. Model effects on production, profit, GHG, N leaching5. Effects of year to year climate variability
DAIRY INTENSIFICATION
DAIRY INTENSIFICATION
Since 1990:• 78% increase in dairy land area• 20% increase in SR (cows/ha)• 85% increase in total no. cows
DAIRY INTENSIFICATION
Since 1990:• 78% increase in dairy land area• 20% increase in SR (cows/ha)• 85% increase in total no. cows
Increased feed intake per hectare• Pasture utilisation• Increased use of nitrogen fertiliser• Increased use of bought-in supplements
DAIRY INTENSIFICATION
Since 1990:• 78% increase in dairy land area• 20% increase in SR (cows/ha)• 85% increase in total no. cows
Increased feed intake per hectare• Pasture utilisation• Increased use of nitrogen fertiliser• Increased use of bought-in supplements
MILK PRODUCTION INCREASED 130%
PROBLEMS OF INTENSIFICATIONMore cows and high N feed: More N fertiliser:
methane
nitrate leached
URINE
nitrous oxide
N fert
REDUCING THE IMPACT1. Fewer animals2. Efficient animals3. Stand-off pasture – less nutrient loss4. Low N feed supplements5. Less N fert use, nitrification inhibitor
Small effects in isolation
STACKED TECHNOLOGIES
PARAMETER BASE FARM EFFICIENT FARMStocking rate (cows/ha) 3.0 2.6Cow genetic merit (BW) 60 120Replacement rate 23% 17%Feed Pasture Pasture + maize grain Stand off pasture No YesEffluent area (% of farm)
20 24
N fertiliser area 180 kg N/ha 50 kg N/ha/yr + nitrification inhibitor
MODELLED DAIRY FARMS
WAIKATO CLIMATE EFFECTS
• Rainfall 1100 mm, temperate climate
• Summer rain: more pasture → milk, profit
• Winter rain: nitrate leaching, nitrous oxide
• Base vs efficient farm:
Low Medium High production Dry Average Wet summer
945 mm 1056 mm 1197 mm rain/yr
WAIKATO SUMMER RAINFALL
Dec Jan Feb Mar0
50
100
150
200
2502003/04
2004/05
2007/08
mm
WHOLE FARM MODEL Pasture production Grain fed Milk production Profit Methane Urinary N
APSIM Nitrate leaching
OVERSEER Total GHG
• Management
• Daily climate
• Management• Annual
rainfall
MODELLING FRAMEWORK
PASTURE PRODUCTION
Dry Average Wet0
5
10
15
20 BaseEfficient
t DM
/ha/
year
TOTAL FEED INTAKE
Dry Average Wet02468
101214
BaseEfficient
t DM
/ha/
year
8% 4% 1% maize grain
MILK PRODUCTION
Dry Average Wet0
200400600800
100012001400
BaseEfficient
kg M
S/ha
OPERATING PROFIT
Dry Average Wet0
50010001500200025003000350040004500
BaseEfficient
$/ha
METHANE EMISSIONS
Dry Average Wet012345678
BaseEfficient
t CO
2 eq
/ha/
yr
TOTAL GHG EMISSIONS
Dry Average Wet0
2
4
6
8
10
12
BaseEfficient
t CO
2 eq
/ha/
yr
N LEACHING
Dry Average Wet0
1020304050607080 Base
Efficient
kg N
/ha/
year
CONCLUSIONSEfficient farm systems:
•Milk production ↑ 8-17%•Profitability ↑ 18-80%•GHG ↓ 23-27%•N leaching ↓ 30-50%
Impact of climate:•Efficient always best•Variability high for leaching, profit
This research was funded by: