absolutely no reason to use it as foliar additives. lots of additives/nutrients recommand foliar feed but they are wrong. foliar uptake is based on the POD of the salt and most of the salt are not suitable because their POD is too high.Magnesium sulfate , for example , is often recommanded for foliar feeding in case of mg def, but this is not effective.Much more effective to apply at rootzone.
The only suitable and common salt for foliar feedings is calcium chlroride, magnesium nitrate and calcium nitrate. Some organic extracst are beneficial too , like kelp/seaweed but thats a different subject.
keep it simple and stay away from AN.
peace