Healthy Soil
Healthy soil is home to billions of microorganisms that feed on organic matter in the soil. Organic matter could be leaves, grass clippings, manure, buried wood, shed grass roots, or almost any biodegradable material that enters the soil to release nutrients.
Sandy Soils
Coarse-textured soils are those high in sand, so adding organic matter to sandy soil will help with water retention and provide additional nutrients. For extremely sandy soil, a mix of soil to organic matter as high as 50/50 may be needed.