It is used as fertilizer for alkaline soil. It is also used as welding flux and fire retardant for fabrics; agricultural spray additive of water-soluble pesticides, herbicides, and fungicides; acidity regulator for flour and bread in food, catalyst for caramel, medium for culture of saccharomycetes by fresh yeast; protein precipitation, chromatographic analysis reagent, urine test, and preparation of haploid breeding medium in biological agents; and salting-out agent in medicine. It is also used as a dyeing auxiliary for acid dyes and a deliming agent for leather.