Fibrophos PK fertiliser - Phosphate and Potash fertiliserGrassland, cereals, oilseed rape, peas, beans and potatoes have all been shown to thrive on fibrophos PK Phosphate and Potash fertiliser fed soils. Extensive trials show fibrophos to be a most effective source of P and K across the whole farm.Raises Phosphate and Potash indicesfibrophos PK Fertiliser raises the soil Phosphate and Potash indices on the poorest land and packs the soil again with all the other nutrients that are needed by the growing crop, except Nitrogen. The immediate effect is increased yields across a much more productive, well-fed acreage.