Soil Chemistry 101
Across a wide range of soils, we often start with pH. That matters, but it is only a small piece of the puzzle. Once pH is understood, we can make informed decisions about lime sources and, when appropriate, gypsum if calcium is needed without adding carbonate. These amendments influence the chemical side of the soil, which then drives how the soil functions in the field.
As calcium levels and ratios improve, soil structure begins to change. Porosity increases, water movement improves, and roots are better able to explore the soil profile. These improvements are a direct result of getting the chemistry right.
I like to picture soil as layers of paper. When we stack basketballs, representing calcium, between those layers, we create larger pore spaces and better aggregation. Magnesium also plays an important role and is necessary for plant and soil function. In some cases, especially on lighter or sandier soils, additional magnesium may be needed. However, when magnesium becomes excessive relative to calcium, it behaves more like filling those layers with marbles. The soil packs tightly together, reducing pore space. In these situations, the soil can look fine on a soil test, but it often feels tight, dense, and poorly structured in the field.
This is where pH, base saturation, and CEC all come together. pH sets the chemical environment, base saturations influence structure and function, and CEC defines how much the soil can hold and exchange. The goal is not to chase a single number, nor is this a direct promise of higher yield. Instead, proper balance acts as an insurance policy for good soil structure.
Well-structured soil supports better biological transfer, improved nutrient movement, healthier root systems, and greater resilience to stress, including drought. When these pieces are understood together, soil performance starts to make sense both on paper and in the field.
