Identifying the type of cation related to fertilizers

[killswitchengage]

Hi
First of all i am not a chemical engineer just a geotechnical guy trying to produce a PhD. I have been given nitrates and phosphates by a peasant for this purpose but he doesn't know the full formula of these powders ( i am referring to the cation linked with them as in potassium nitrates or magnesium phosphate ...etc) . Can i somehow manage to identify what type of cation with simple home tips or whatever ( i know it may sound stupid but for the time being i am just not that free to go and test them in a qualified lab , both powders are white if it may help )

 

[Compositepro]

Dip a red-hot wire into the powder and then place it in a flame of a propane torch. The color of the flame should be able to distinguish between sodium, potassium, or magnesium.

https://en.wikipedia.org/wiki/Flame_test

 

[bimr]

The sources of nitrogen used in fertilizers are many, including ammonia (NH3), diammonium phosphate ((NH4)2HPO4), ammonium nitrate (NH4NO3), ammonium sulfate ((NH4)2SO4), calcium cyanamide (CaCN2), calcium nitrate (Ca(NO3)2), sodium nitrate (NaNO3), and urea (N2H4CO). Phosphorus is generally supplied as a phosphate, such as diammonium
phosphate ((NH4)2HPO4) or calcium dihydrogen phosphate (Ca(H2PO4)2). Potassium comes from potassium sulfate (K2SO4) or potassium chloride (KCl), which is also called muriate of potash.

Don't think it will be easy to do.