To prepare suspension fertilizers from nitric acid solutions of phosphate rock the solutions are neutralized in an already neutralized solution in a vessel by means of ammonia and/or an ammonium salt of carbonic or carbamic acid, a pH of from seven to 10 and a temperature of from 10.degree. to 50.degree. C. being maintained. During or immediately after the neutralization, substances containing carbonate ions and/or forming carbonate ions in solution are introduced. The finished suspension should have a CO.sub.3 .sup.(--) content of at least 0.2 percent by weight.
