Petroleum coke circulating fluidized bed combustion product as a sulfur source for alfalfa

Petroleum coke circulating fluidized bed (CFB) combustion product is created when petroleum coke is combusted with limestone in a circulating fluidized bed boiler. The CFB product contains high concentrations of sulfur (S), nickel (Ni), and vanadium (V). Using it as a S source is encouraged, but little information is available related to plant responses and environmental impact. The CFB product was applied at rates of 0, 11, 33, and 110kgS ha(-1) to two agricultural soils (Canfield silt loam and Wooster silt loam). Dry weight of alfalfa (Medicago sativa L.) and S in plant tissue was increased by the S treatments. Concentrations in alfalfa of V were increased but did not reach environmental concern levels. Concentrations in alfalfa of Ni were not increased. In the soils, only total S and plant available S were increased by these materials. No soil contamination problems were observed when CFB product was used as an S source.