La Motte Soil Test KitWhile no home kit can give the accuracy of a lab test, La Motte comes close and certainly has the advantages of convenience and cost effectiveness. Follow instructions to mix a soil sample with a reagent solution in a test tube. Compare the resulting color to standards on laminated color charts. Includes 30 pH, 15 nitrogen, 20 phosphorus & 15 potassium tests. Complete information for interpretation (2 booklets). pH preference guide for over 600