Fertilizer question, please

[DonnaMarieNJ]

I found this on google and I didn't want to have to buy something special for the blueberry plants, and another for the rasperry and blackberry plants, and yet something for the citrus and fig:

"Blackberries respond well to any nitrogen-rich fertilizer, but blueberries require fertilizers with an ammonium form of nitrogen such as urea, sulfur-coated urea, ammonium sulfate, or cottonseed meal. Any fertilizer sold for azaleas or rhododendrons also works well for blueberries."

I don't know if this is true, but I'm just trying to make my life easier and not spend as much money.