On the other hand, a soil test for organic matter, Available Phosphorus, Exchangeable Potassium, Magnesium, Calcium, Soil pH, Buffer pH, Cation Exchange Capacity, Percent Base Saturation of Cation Elements, Sulfur, Zinc, Manganese, Iron, Copper, and Boron including recommendations costs just under $20 at the one lab I checked. One might easily spend more than that guessing and trying different things.
