Considering gypsum

Reusing waste materials is easier with a basic understanding of their composition. Readers of this column will recall my experiments in upcycling oyster shells into decorative, traction-enhancing calcium supplements and cardboard into weed suppressant that breaks down into carbon-rich soil enrichment.

According to the soil science course I've been taking, we needn't concern ourselves with supplementing calcium in the soil. Inorganic supplementation (here, gypsum or lime) will only provide a temporary boost, and most of it will leach away over time -- especially with the South Sound's volume of...