From the OSU Extension:
An Ohio State University scientist says an abundant byproduct from coal-burning power plants, if spread on farmers’ fields, could help control Lake Erie’s harmful algal blooms.
a soil biochemist in the university’s (CFAES), said applying to crop fields can keep soluble phosphorus, the main nutrient feeding the algae, from getting washed from the soil by heavy rains, then running off into streams and rivers and eventually into the lake.
“Not only that, but FGD gypsum, which is a synthetic form of gypsum, can improve both the soil and the crops,” he said. “Naturally occurring, mined gypsum has a long history as a soil amendment and fertilizer for farming.”