Yes. There are many kinds of salts. Not just the typical Sodium Chloride that we think of when we hear that word. At the risk of starting a huge war, I'm going to throw out my opinion that no matter the source of nutrient, N - P - K, whether it comes from a chemical formulation or a natural formulation, the soil/plants don't care where it comes from. Nitrogen is still nitrogen, no matter where it comes from. But, I do agree that when the nutrients are found in a natural form, there are micronutrients available, which may make the macronutrients more bioavailable. And a natural form may be slower release.