Sulphur deposition has been decreasing in the past few decades and now crop requirements are not being met in some situations. A preliminary forage trial showed that S fertilization can increase forage yield, quality and profit. Currently there are no Ontario recommendations for fertilizing alfalfa or other crops with S, no Ontario S soil test and the alfalfa critical tissue concentration is under review. This project will provide data on rates, sources and timing of application and tools to identify fields with potential for increased yield, quality and profit through S application. This is the second year for the trial. The Heartland project is in conjunction with a larger S research project in collaboration with University of Guelph. In 2014 we also evaluated K uptake and removal, and effect on soil K levels.