I want to add nitrogen to my soil samples in a lab as fertilizer (ammonium nitrate). I need to add it equivalent of 50 kgN/ha. I have a clump of soil, that weighs 20g. What is the best way to convert it to concentration, molarity or any other measure of how to prepare my fertilizer solution without knowing density, depth or any similar physical properties of the soil.
Basically, I would like to know if there is a way to convert nitrogen load from kg/ha to 20 gr. Thanks everyone in advance!