1. Mineralparticles (sand particles are largest, silt is medium sized, clay is the smallest or finest) are the “bones” of the soil; Good soil, or “loamy” soil, has at least two or all three sizes of these particles. They come originally from rock.
2. Organic matter is once-living matter (like plants, animals, insects, animal waste) in various stages of decomposition.
3. Biota (bacteria, fungi, protazoa, mites, worms, ants, etc) are living organisms that decompose organic matter. This converts nutrients into forms that are accessible to plants. Larger organisms like worms also create space in the soil.
4. Porosity is the presence of pores/spaces made by roots and biota, which allows for water and nutrients to reach roots and for roots to grow.
