4 Reasons to Have Your Soil Tested A soil test is a process by which elements measured for their "plant available" content within the sample. The quantity of available nutrients in the sample determines the amount of fertilizer or other soil amendments that are recommended. A soil test also measures soil pH, organic matter, and cation exchange capacity (CEC). These analyses indicate whether lime, elemental sulfur, or iron is needed and, if so, how much to apply. | |