Summit Quinphos
Fertiliser application on farmland
Why do farmers apply fertiliser?
• All living organisms require some basic
chemical elements to function i.e. to build
DNA , cells walls etc
• The major elements required are;
– nitrogen, phosphorus, potassium, sulphur,
calcium and magnesium
• If any one of these elements is deficient
– grass will not grow
– or will not grow as well as it could
Why do farmers use fertiliser?
• To over come nutrient deficiencies
• To replace nutrients transferred:
– off farm in production i.e. milk, meat,
wool,crops
– to unproductive areas of the farm i.e. effluent
ponds, tracks
What are the environmental problems
associated with fertiliser application?
• Phosphate runoff
– Approximately 80% of the phosphate in our
waterways comes from agricultural runoff
• Nitrate leaching
– A study in the late 80’s indicated that up to 20%
of ground wells in Taranaki and Waikato had
over 10mg/l nitrate
– The recommended maximum level is 11.3mg/1
These affect water quality
• By causing algal
blooms and excessive
weed growth which
– stops us drinking it
– stops recreational
activity
– stops us eating the fish
– and kills aquatic life
How do excess nutrients get into
waterways?
• Direct application
– animals depositing directly in waterways
– fertiliser spreaders applying too close to waterways
• Erosion
– pugging & compaction
• Runoff
– surface runoff
– sub-surface runoff
• Leaching
What does Summit Quinphos do to
minimise the environmental effects
• Design a fertiliser plan for each farms
specific needs.
– This includes:
•
•
•
•
Nutrient budgeting
GPS Soil & Herbage testing
Farm Environment Maps
Summit Quinphos environmentally protective
fertiliser
What is Nutrient Budgeting?
• It is a balance of nutrients onto and off the
farm
• Works in a similar manner to a financial
budget
• A fertiliser recommendation is using a
simple form of nutrient budgeting
How do we do it?
• Use fertiliser recommendation models
• Or more advanced nutrient budgeting
computer models e.g. Overseer
The information Overseer uses includes:
•
•
•
•
•
•
Inputs
Stock & production information
Climate data
Topography
Soil type & fertility
Fertiliser
GPS Soil & Herbage Testing
• Soil & herbage tests done at least every 2 years
• Soil tests show what nutrients levels are in the soil
and show trends over time
• Herbage tests are needed to fine tune a fertiliser
programme in the short term
– tests for trace elements
– checks on how well the grass is taking up the major
elements in the soil.
GPS - Global Positioning
Systems
• Uses satellites to accurately locate where
soil & herbage tests have been taken:
– Which increases reliability and accuracy of soil
& herbage testing so;
– I can give farmers better advice.
Summit Quinphos Environmentally
Protective Fertiliser
• RPR - Reactive Phosphate Rock
• Sustain
• Protect PAPR
What is Reactive Phosphate Rock
(RPR)
• RPR’s are natural minerals formed on the ocean
floor over thousands of years
• Over time dead sea organisms form layers
• In certain areas these layers become enriched with
phosphate absorbed from sea water
• And form a mineral which is part phosphate and
part calcium carbonate (lime)
How does RPR work?
• RPR’s chemical structure is very unstable
– Because of the carbonate in the rock;
– Which means RPR can be dissolved by the weak
organic acids in the soil.
• Superphosphate comes from hard phosphate rocks.
– These rocks are very insoluble.
– To release the phosphate so plants can use it;
– The hard rock needs to be treated with a very strong
acid (sulphuric acid).
PHOSPHATE SOURCES
HARD PHOSPHATE ROCK REACTIVE PHOSPAHTE ROCK
+
minus
SULPHURIC ACID
CALCIUM
=
SUPERPHOSPHATE
=
PLANT AVAILABLE
PHOSPHATE
+
PHOSPHORIC ACID
+
AMMONIA
=
TRIPLE SUPERPHOSPHATE
DI - AMMONIUM PHOSPHATE
18 N 20 P 2 S
21 P 2 S
=
Key Factors Affecting RPR
Availability
• Two key factors affect the ability of RPR to
be dissolved
1 How acidic the soil is
2 How easily calcium can move away from the RPR
particle i.e. rainfall
– These two factors mean that the breakdown of
RPR is a gradual process (slow release)
Phosphate Runoff
• Approximately 80% of the phosphate in our
waterways comes from agricultural runoff
• Research in NZ & Ireland shows that a
significant, and often the major proportion of
this runoff comes directly from recently applied
water soluble phosphate fertiliser
– Superphosphate, Triple Superphosphate, DAP
Reactive Phosphate Rock (RPR)
• Research has proven that runoff from RPR
is 25 times less than Superphosphate
• This is because:
– is not water soluble
– has a greater density than water soluble
phosphate
Nitrate Leaching
• Dairy cattle numbers have gone from 2.9
million to 4.1 million
• N fertiliser use has gone from 117,000
tonnes of N in 92/93 to 333,000 tonnes in
01/02
• A cows urine patch contains the equivalent
of 500-1000 kg N/ha
Nitrate Leaching cont..
• At normal rates of application leaching
losses from nitrogen fertilisers are typically
5-10% of nitrogen applied.
Sustain
• Sustain is urea that has been coated in
Agrotain & Sulphur.
– Sustain reduces leaching losses of nitrogen.
– And also reduces ammonia volatilisation losses
to the atmosphere
Sustain
• Agrotain slows the breakdown of the urea.
– Urea breaks down over 0-2 days
– Sustain breaks down over 0-10 days
• Slowing the breakdown of urea gives the
plant more opportunity to take up nitrogen
therefore leaving less nitrogen available to
be leached.
Protect PAPR
• PAPR - Partially Acidulated Phosphoric
Rock
• RPR is reacted with phosphoric acid
– in a similar process to superphosphate
• It combines both water soluble phosphate
and slow release phosphate.
• Has less runoff than superphosphate
Farm Environment Maps
• The Farm Environment Maps include:
• information on soil type
– this helps me decide where on a farm to soil test
• information of the risk of phosphate loss
from:
– water soluble phosphate
– RPR phosphate
• The maps can help me decide what form of
phosphate fertiliser to use on a particular
farm
• Will include information on the risk of
nitrate leaching
• And faecal bacteria runoff
In Conclusion
–
–
–
–
–
The Farm Environment maps
GPS soil & herbage testing
Nutrient budgeting
Summit Quinphos fertilisers
And talking to the farmer
All help me to produce a fertiliser plan that is
specific to a particular farms requirements and
at the same time minimise the environmental
risks of applying fertiliser.