• Bert Quin

Quinfacts - RPR Series (9)

9. Quin Environmentals Provides Two Quinfert RPR Grades (V1 and V2)


Solely due to games being played by the industry, Quin Environmentals (NZ) Ltd has decided to make 2 very slightly different grades available to farmers.


V1 or ‘HRPR’ was field-tested by the IFDC, and rated by them as a Highly Reactive Phosphate Rock. It performed even better than North Carolina RPR in published response trials conducted by the IFDC.  It contains 12.7% P, 35% Ca, 0.8 % Mg (as free dolomite present in the deposit) and 1.3% S.


Note however  that the small amount of free dolomite present naturally in V1 (5-7%) slightly reduces its solubility in the obsolete 30-min citric P test (citsol test) used in NZ (and now nowhere else in the world, to my knowledge). This small amount of dolomite has NO EFFECT on its excellent field performance. Ironically, the very same people who mix Sechura RPR with Moroccan rock and call the mix an RPR are arguing that V.1 should not be called an RPR. Go figure.


V2. Is Algerian RPR from the very same deposit, with very slightly more P (12.75% total P) due to some of the dolomite being removed (magnesium content reduced t0 under 5%). This product meets the obsolete NZ citric solubility test.


If you wish, you can choose whether you want V1 or V2. Same price. They perform the same as one another. You get 0.2% more Mg in V.I or 0.05% more P in V.2. Your choice. Let us know. It’s all a bit trivial, don’t you think? I think so. But then, I’ve only been researching RPRs for 41 years…


Bert Quin

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