Please follow http://www.nrcs.usda.gov/wps/portal/nrcs/detail/?ss=16&navtype=SUBNAVIGATION&cid=nrcs143_014203&navid=120110120000000&pnavid=120110000000000&position=Not%20Yet%20Determined.Html&ttype=detail&pname=Fate%20and%20Transport%20of%20Nutrients:%20%20Phosphorus%2.