Rock Phosphate Organic Fertilizer (50lb) | Planet ...
An organic, untreated Soft Rock Phosphate (030) with colloidal clay containing valuable trace minerals in addition to phosphorus. Since phosphorus is lacking in most soils, fertilizer applications are a must for superior results. Calphos™ contains a minimum of 3% available (and a minimum of 20% total) phosphoric acid (P2O5) and 20% Calcium (Ca).