Phosphorus runoff is causing blooms of harmful algae that deplete waterways of oxygen, resulting in “dead zones” that damage ecosystems vital for aquatic life. It’s a problem in many of the waterways we all depend on for recreation and drinking water, including the Great Lakes and Chesapeake Bay. Just last year, Maryland’s outgoing governor proposed land use regulations designed specifically to reduce phosphorus runoff in the Chesapeake watershed.Coal fired power plants, particularly one with the newer pollution control systems produce a lot of gypsum, far more than can be used by the wall board industry. Perhaps the farmers on the Eastern Shore could become customers, and use the gypsum to reduce phosphorus runoff. This is one of main goals of the "Bay Diet."
USDA’s Agricultural Research Service (ARS) scientists have been looking for ways to address the problem by using gypsum, which binds with phosphorus in the soil and prevents it from running off. There is no shortage of gypsum. In fact, one type is a byproduct of scrubbing the sulphur out of power plant emissions and is used to make wallboard.
Studies by ARS soil scientist Allen Torbert, Dexter Watts and their colleagues at the National Soil Dynamics Laboratory in Auburn, Alabama, have shown that when this industrial gypsum is applied to the soil with poultry litter, it reduces phosphorous runoff by 50 to 60 percent. Torbert and colleagues working in Beltsville, Oxford and elsewhere, also have found that gypsum reduces the potential for pathogens, such as E. coli, in poultry litter and cow manure to be transported in runoff and reach drinking water supplies. The gypsum improves soil infiltration and curbs algae growth by binding with phosphorus in the soil, so that less phosphorus is available to algae as a nutrient.
If this article is to be believed, gypsum is the magic secret for agriculture: 37 ADVANTAGES TO USING GYPSUM