Disease-suppressive soils are soils with lots of microorganisms sythesizing antibacterial substances, as well as having no insect occurrence, referred to as "bacteria-cleansing type of soils". Also, soil with less than 5% Fusarium and have very active Penicillium, Trichoderma, and Streptomyces, and the appearance of insects is scarce. There is less odor even though living organic matter with high contects of nitrogen are manured and it smells like mountain topsoil. Crumb formation in the soil is relatively hastened and water permeability is improved. Harvest is somewhat less although diseases are not observed. However, when the synthetic type of soil is combined with this type of soil, high productivity is achieved.
From: Agricultural Utilization Of Microorganisms For Environmental Conservation. D.r Teruo Higa. page 17.