Most gardeners are used to granular fertilizer which dissolves easily in water. It has no staying power and often times, minerals are leached into the soil. Crystalline fertilizer has bigger particles which dissolve over time because of the bigger surface area resulting in more nutrients available to the plants for less fertilizer saving on costs.
A dry crystalline material I know for fertilizing is Ammonium sulfate; in which the nitrogen is all in the ammonium form. Produced by two methods—by-product and synthetic. Used for direct application and blended complete fertilizers. Broadcast or sidedress. Can be left on surface or incorporated into soil. Contains 24% sulfur.
