Chatham rock phosphate use will improve water quality

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NEWS RELEASE 17-26 24 October 2017

Chatham rock phosphate use would improve water quality by dramatically reducing
farm run-off, says CRP

Chatham Rock Phosphate (NZ: CRP, TSX.V: NZP) (“CRP” or “the Company”) this week
advised that improved water quality will result from the use by farmers of Chatham rock
phosphate.

Fertiliser run-off into waterways can be dramatically reduced, without any loss of
production, by using naturally occurring reactive phosphate rock (RPR), according to
Chatham Rock Phosphate chief executive Chris Castle.

Mr Castle said scientific studies over many years have shown RPR offers strong
environmental benefits.

Studies comparing the use of RPR and superphosphate on farmland show that, when
applied directly, RPR is both a very effective sustained-release fertiliser and not
susceptible to run-off.

CRP holds New Zealand’s only material source of RPR.

The findings of the studies – some going back decades – are supported by Dr Bert Quin,
probably New Zealand’s pre-eminent expert on the use of different phosphate rocks as
phosphate fertilisers. Dr Quin designed and coordinated New Zealand’s ‘National Series’
of RPR vs superphosphate field trials while working as a senior government agricultural
research scientist during the 1980s.

Dr Quin believes phosphate nutrient continues to enter waterways from agricultural
land mainly because we use predominantly water-soluble types of chemically-
manufactured phosphate fertiliser, especially single superphosphate (‘super’), which
supplies phosphorus (P) and sulphate-sulphur.


“Super is prone to run-off of applied phosphorus into waterways during run-off events
in the first 8-10 weeks after application, entering streams, rivers and lakes, and causing
eutrophication in the form of excessive water-weed growth and algal blooms” says Dr
Quin. “It can even be leached right through soils with low phosphorus retention such as
those in Northland and on the West Coast.

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Dr Quin estimates switching from superphosphate to RPR and RPR/DAP (diamonium
phosphate) blends would reduce average run-off losses of phosphorus by 80%.

“This would take P losses back below the trigger levels that have resulted in most of our
lakes becoming eutrophied. Within 5-10 years, water quality in the Rotorua lakes, for
example, would be massively improved.

“By far the most cost-effective option for phosphorus is reactive phosphate rock or
‘RPR’. This is a natural mineral, formed on the sea floor originally, which is a very
effective source of sustained-release phosphorus, ideal for maintaining high-producing
pasture and extremely resistant to run-off losses”.

Dr Quin says that he has been very disappointed that the NZ fertiliser industry, ironically
largely comprised of a duopoly owned by farmers, has not had the courage to follow the
example set by Summit-Quinphos over the period 1989 to 2007. “For their
management to replace true RPR with agronomically ineffective ‘direct application
phosphate rock’ from Morocco is as cynical as anything I have seen” he says. “The time
is right for people with the political will and determination to save New Zealand’s
environment to stand up and force change”.

He also says anecdotal evidence over the nearly 30 years some New Zealand farmers
have been using RPR shows maintenance requirements for phosphorus start to drop
significantly because of both reduced run-off and reduced fixation onto soil clay
particles. The higher P run-off from soluble P in the 8-10 weeks after application comes
largely from particles and granules of the soluble fertiliser being floated off in run-off.
RPR particles are 50% heavier. At the other end of the scale, the very low pH that exists
around granules of super lead to increased fixation of P onto allophanic clay particles. So
it is a lose-lose for super.”

He believes there is a need for specific advice for farmers regarding managing or
minimising any minor lag in production following a switch to RPR. “The easiest way is to
use a bit of DAP mixed with the RPR for the first 2 years”.


About Chatham Rock Phosphate

Chatham Rock Phosphate is the custodian of New Zealand’s only material resource of
environmentally friendly pastoral phosphate fertiliser. Our key role is connecting the
resource with those who need it.

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Using this phosphate will support sustainable farming practices, including healthier soils
and reduced accumulation of the heavy metal cadmium, dramatically lowering P runoff
to waterways and shrinking fertiliser needs over time.

The resource has an estimated worth of $5 to $7 billion, representing one of New
Zealand’s most valuable mineral assets and is of huge strategic significance because
phosphate is essential to maintain New Zealand’s high agricultural productivity.

New Zealand’s current access to phosphate is vulnerable to economic and political
events in the six countries controlling 98% of the world’s phosphate reserves, with 85%
of the total in the Western Saharan state of Morocco.

Chatham takes very seriously the responsibility vested in it through its mining permit to
use the world’s best knowledge and technology to safely extract this resource to help
sustainably feed the world.

Our initial environmental consenting process established extraction would have no
significant impact on fishing yields or profitability, marine mammals or seabirds.


Other New Zealand and international research

Reports of research into P run-off into waterways by New Zealand and overseas
scientists considered by CRP were:

1. RPR revisited (1): Research, recommendations, promotion and use in New Zealand
by BF Quin and M Zaman.

2. RPR revisited (2): Long-term farmer experience helps define the role of RPR in
grazed pastures by M Zaman and BF Quin.

3. Phosphorus fertiliser form affects phosphorus loss to waterways: a paired
catchment study by R. W. McDowell, R. P. Littlejohn and J. D. Blennerhassett.

4. Evaluation of two management options to improve the water quality of Lake
Brunner, New Zealand by RW McDowell.

5. Potential phosphorus losses in overland flow from pastoral soils receiving long-term
applications of either superphosphate orreactive phosphate rock by RW McDowell,
RM Monaghan and PL Carey.

6. Rainfall intensity and phosphorus source effects on phosphorus transport in surface
runoff from soil trays by Francirose Shigaki, Andrew Sharpley and Luis Ignacio

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Prochnow.

7. Phosphorus Leaching in an Acid Tropical and Triple Superphosphate by E Gikonyo,
AR Zaharah, MM Hanafi, and R Anuar.

8. Effectiveness of rock phosphate, coastal superphosphate and single
superphosphate for pasture on deep sandy soils by MDA Bolland, MF Clarke, and JS
Yeates.

Contact Chris Castle on 021 55 82 85 or chris@crpl.co.nz