RPR (reactive phosphate rock) is a slow-release phosphate fertiliser ideal for maintaining levels of phosphate in the soil.
RPR breaks down under acid soil conditions, releasing phosphate to the soil over time. The release of phosphate from RPR increases with soil moisture.
Using RPR has a number of benefits, including minimal phosphate losses through leaching and run-off.
RPR can be safely mixed with dolomite, magnesium oxide or elemental sulphur.