We don’t use acid to make the phosphate available to plants, just natural products and processes. Therefore it doesn’t raise the soil acidity, in fact quite the opposite. Our fertiliser will lower the soil acidity to the optimum acidity, so it effectively does the job of traditional fertiliser and lime combined.
CarboPhos has a high carbon content. This is one of the most overlooked aspects of fertiliser. Carbon will raise the soil’s organic matter, which effectively makes any mineral (phosphate, nitrogen, potassium etc) more available to the plant by improving soil biology. This point is particularly important with nitrogen – when you build up the carbon in the soil there will be a natural build up of nitrogen as the bacterial foodchain excretes excessive nitrogen. Putting synthetic high nitrogen fertilisers directly into the soil can not only cause pollution from run-off, it can actually suppress the natural nitrogen cycle in the soil. If the soil is instead fed with carbon there will be a natural balance of nitrogen in the soil that will be made available to plants.
When soil is in balance the natural processes take over, and worms will reappear. Worms castings are naturally good for the soil, and trials have shown that potassium makes up approximately 14% of their castings. Therefore as you get your soil working again the potassium the plants need will be provided naturally. Further potassium supplied by synthetic means increases leaching as it is very water soluble.
Our product is less than 20% water soluble (traditional phosphates fertiliser are about 80%) so there is minimal leaching, therefore less pollution in waterways and less waste of nutrients.
The specification for RPR was originally developed by Dr Bert Quinn; he has called it a guideline rather a fixed specification. For RPR he suggested the citric solubility should be at least 30%. Subsequent work has been done which considers the effect of the fineness of grind. A paper has been produced and you can read it here
. Its mind boggling stuff. Basically, its says if the rock is finely ground it can have the same effect as citrilc solubility on the availablility of the P. We are simple folk so we trialed various rocks, and we found fine grind non-RPR slightly out performed RPR in our tests, so we use it! To be honest we do not believe there would be any detrimental effect from using a RPR, and if your soil was quite acidic there would probably be additional benefit, but as your soil moves into balance that additional benefit will disappear.