Reducing Phosphorus Export from Croplands with FBC and FGD By-Products

摘要

Excessive soil P levels cause high concentrations of water soluble P in soil, thereby increasing the potential for P export to streams. Converting water soluble P to less soluble forms with lime or Ca containing coal combustion by-products can reduce the release of soil P to runoff. A typical agricultural soil at excessive soil P levels was incubated with four treatments (0 to 20 g kg~(-1)) of fluidized bed combustion flyash (FBC) and a flue gas desulfurization (FGD) by-product. A 10 g kg~(-1) application of FBC and FGD to soil reduced the concentration of water soluble P by 60% and 50%, respectively. Projection of these results over an agricultural watershed indicates that treating only 4% of the watershed can reduce the loss of water soluble P by 30%.