benefits: It improves many qualities of the soil it is applied to: it increases water infiltration (and thereby decreases runoff and erosion), allows problem nutrients to be leached away, buffers soil pH, and improves the structure of clay soils.
how it works: Calcium sulfate makes sodium soluble so it separates from soil particles. Treated soil is "loosened" so that root hairs can feed on all available nutrients and moisture.
how to use it: Follow the manufacturer's guidelines, of course. We like to apply a yearly top dressing of gypsum, and then spread mulch on top of that, and water well.
why we like it: Gypsum is an inexpensive, non-toxic soil amendment that is widely available and is approved by the International Federation of Organic Agriculture Movements (IFOAM).
remember: Gypsum is especially helpful for hard clay soils, but it doesn't work overnight. It can take up to three years for full effects to take hold.
