16. What actually is an RPR? The stated knowledge in 2019. Updated from the original version of 2016 The expression ‘RPR’, or reactive phosphate rock describes a phosphate rock that – with certain provisos like soil pH of 6 or less, and an annual minimum of 800mm rainfall and/or irrigation – will adequately … Read more
15. ‘Dicalcic’ vs Reactive Phosphate Rock (RPR), elemental S and Fine Lime (updated September 2019) What exactly are you getting for your money? Dicalcic Super Dicalcic (aka lime-reverted superphosphate) has been around a long time. When properly made, the water-soluble P component in super, called monocalcium phosphate or MCP, is fully converted after … Read more
14. Quinfert Algerian RPR; All the facts
13. An Open Letter to New Zealand Dairy Farmers An open letter to New Zealand dairy farmers: December 2018 ‘A farmer-lead way to sorting out the environmental circus’ Dr Bert Quin, Managing Director, Quin Environmentals (NZ) Ltd The background The dairy industry in New Zealand has grown much faster than anyone envisaged, and way … Read more
12. The Sources and Causes of Soil P Losses and the Role of RPR in Reducing Them RPR Revisited 5: The Sources and Causes of Soil P Losses and the Role of RPR in Reducing Them 1Bert F. Quin and 2Gordon Rajendram 1Quin Environmentals (NZ) Ltd 2Eurofins NZ Ltd Presented to … Read more
11. An open letter to New Zealand farmers
10. The potential of RPR I have been involved with RPR research and promotion in New Zealand for 40 years. I spent 17 years as a soil fertility research scientist with the Agricultural Research Division of the Ministry of Agriculture – what became AgResearch – including 3 years as Chief Scientist (Soil Fertility) at … Read more
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 … Read more
8. The time has come for New Zealand to completely stop making superphosphate The National Series of RPR vs superphosphate trials, ran for 3 to 7 years in the 1980s on 19 sites throughout New Zealand. The sites were deliberately chosen to have below-maintenance levels of soil Olsen P. This was done to make … Read more
7. The facts about serpentine superphosphate 1. Serpentine is a natural magnesium-calcium silicate. It is widely used as a slow release magnesium (Mg) fertiliser in finely ground form. In the case of the product called ‘serp-super’, about 25% by weight of finely ground serpentine is added to the freshly-made superphosphate, before the sulphuric … Read more