This is because dissolved orthophosphates are usually
the limiting nutrient for algal blooms. Currently, available techniques to control eutrophication are surprisingly
scarce. Calcium sulfate or gypsum is a common soil amendment and has a strong complexation to
orthophosphates. The results showed that calcium sulfate reduced the amount of water extractable P (WEP)
through soil incubation tests, suggesting less P loss from farmlands. A greater decrease in WEP occurred with a
greater dosage of calciumsulfate. Compared to conventional coarse calciumsulfate, nano calcium sulfate further
reducedWEP by providing amuch greater specific surface area, higher solubility, better contactwith the fertilizer
and the soil particles, and superior dispersibility. The enhancement of the nano calciumsulfate forWEP reduction
is more apparent for a pellet- than a powdered- fertilizer. At the dosage of Ca/P weight ratio of 2.8, theWEP decreased
by 31±5%with the nano calciumsulfate compared to 20±5% decreasewith the coarse calciumsulfate
when the pellet fertilizer was used