Tennessee Brown Phosphate

(0-3-0, 21-25% total P2O5) 40% CaO. The consistency of rich soil. Comes from the washing piles left behind when high-grade ore was extracted to produce superphosphate in the early 20th century. When tested in several midwestern states’ labs, concentrations of available phosphate were regularly over 6%. Lowest concentration of heavy metals of any phosphate source. Recommended by soil gurus Phil Callahan and Mark Fulford. It is best to apply phosphate according to a soil test; if you have not tested your soil but you have reason to believe the phosphorus is low, a suggested spreading rate could be 75 lb per 1000 sq ft.