Calphos Soft Rock Phosphate - Regular Powder (50 lb)

The best natural source of phosphorus and calcium. It is comprised of the bony structures of prehistoric marine creatures mined in Florida from the best deposit in the country. An immediately available and a long-term source of phosphorus. Not the same as the hard rock phosphate, sold by most nurseries and farm suppliers, which is not nutritionally as readily available. Averages 20% P2O5 (3% immediately available), 20% Ca Soft Rock Phosphate should be applied and worked in prior to planting Use at 5 lb/100 sq.ft. or 1 ton/acre on phosphate deficient soils, less on fertile soils Trees and perennials, use 1-10 lb per planting hole, depending on plant size Supplies P and Ca for up to 5 years after application, depending on the crop