The 4th edition of the Soil Health Resource Guide opens with the fundamental question — Why Cover Crop? — and answers it across four categories: above-ground biomass for grazing, wildlife, and pollinators; living roots that feed soil biology and fix nitrogen; soil armor that reduces erosion and evaporation; and decayed root channels that open the soil to air and water. Built as a practical reference, the guide walks through Green Cover's infrastructure and shipping, cover crop opportunities across the season, and detailed information on legumes, grasses, brassicas, broadleaves, and perennials. The SmartMix Calculator sections and mix recommendations by timing — spring, late spring/early summer, late summer, and fall — give farmers a starting point for their own operation. Supporting articles cover insects and pollinators, wildlife, resistant weeds, herbicide carryover, termination, fertility, soil biology, livestock and grazing, drill calibration, and cover crop testing.