The determination of total and extractable molybdenum in soils by acid ammonium oxalate solution (Tamm's solution), by 0.1 N sulfuric acid solution, by 0,03 N ammonium fluoride in 0.1 N sulfuric acid, solution and by 0.1 N oxalic acid solution are described. The extraction of soil molybdenum by the 0.03 N ammonium fluoride in 0.1 N sulfuric acid solution seems to be indi cated for routine determinations of "soluble" molybdenum since the method is simple and rapid. in 0.1 N sulfuric acid, solution and by 0.1 N oxalic acid solution are described. The extraction of soil molybdenum by the 0.03 N ammonium fluoride in 0.1 N sulfuric acid solution seems to be indi cated for routine determinations of "soluble11 molybdenum since the method is simple and rapid.