2. DISEASE-SUPPRESSIVE SOILS
These soils contain lots of soil microbial communities. Most of these microorganisms will be beneficial microorganisms including penicillium, Trichoderma, and Streptomyces genus. The texture is crumbly, where water can penetrate the soil easily. There is a low incidence of soil borne diseases in this soil, and plant yields are high. Due to high populations of beneficial microorganisms, the soil does not have any foul odors.
3. ZYMOGENIC SOILS
These soils tend to be dominated with fermentative microorganisms such as lactic acid bacteria and yeasts. Populations of plant pathogens are low and disease suppression is high. The soil structure is significantly improved and water penetration is even. Unavailable nutrients become available to plants for increased plant health. Microbial metabolites such as amino acids, polysaccharides, vitamins, bacteriocins, plant hormones, etc. are present. The soil is becoming more aerobic, teaming with life and bio-available nutrients for plants. Crop yields will be higher on these fields than on disease-suppressive soils.
4. SYNTHETIC SOILS
"Synthetic" microbes begin to dominate this soil. Unlike the meaning of "synthetic" when used for fertilizer or chemicals. This does not mean a "fake" or "manufactured" soil. It means a soil where things are synthesized or made. These microbes include algae, photosynthetic bacteria, and nitrogen-fixing bacteria. These are fusarium wilt suppressive soils as fusarium has a difficult time producing a strong population. Microbial metabolites are very high and Dr. Higa refers to this soil as being a "bacteria-cleansing type soil" and a natural biological control for soil borne pathogens.