AbstractThis rapid method makes use of the stable yellow colour complex developed when an excess of a molybdate solution is added to an acidified solution of a vanadate and an orthophosphate; all three reagents required can be used in a composite solution. Details for the determination of water‐soluble and total phosphate are given using the Spekker photoelectric absorptiometer. Results agree within 2.5% of those obtained by the standard gravimetric method, those on nine fertilizers being given.