REDUCTION OF EXCESSIVE BIOAVAILABLE PHOSPHORUS IN SOILS BY USING MUNICIPAL AND INDUSTRIAL-WASTES

Poultry and swine production has created both economic growth in Oklah oma and concern over the effect of excessive land application of anima l manure on water quality. The objectives of this study were to evalua te the ability of two drinking water treatment alum hydrosolids (HS1, HS2), cement kiln dust (CKD), and treated bauxite red mud CRM) to redu ce excessive amounts of bioavailable P in soil and to determine potent ial environmental impacts from these treatments. Two soils that contai ned 553 and 296 mg kg(-1) Mehlich III-extractable P, as a result of pr ior treatment with poultry litter or dairy manure, were mixed with ame ndments at the rate of 30 and 100 g kg(-1) soil and incubated at 25 de grees C for 9 wk. Reductions in Mehlich III-extractable P from 553 mg kg(-1) to 250 mg kg(-1) followed the trend HS2, CKD greater than or eq ual to HS1 greater than or equal to RM in the slightly acidic Dickson soil (fine-silty, siliceous, Thermic Glossic Fragiudult). Reductions i n Mehlich III-extractable P from 296 mg kg(-1) to 110 mg kg(-1) follow ed the trend HS2 > HS1 > RM > CKD in the calcareous Keokuk soil (coars e-silty, mixed, Thermic Fluventic Haplustoll). Reduction of soluble P followed similar trends. Most treatments did not result in excessive s oil pH or increases in soil salinity, in extractable Al, or in heavy m etals in soils. Application of alum hydrosolids to soils with excessiv e amounts of bioavailable P in sensitive watersheds may improve drinki ng water quality and provide financial savings for municipalities.