Some soils have been observed to suppress diseases in crops grown upon them. Soils are a rich source of microbes that are thought to help plants suppress pathogens by improving the health of the plant, induce natural plant defense, produce antibiotics, compete against pathogens, or hyperparasitize the pathogen. Soil that suppresses crop disease due to the specific structure of its microbial community is known as disease-suppressive soil. Suppressive soil is an attractive method of biocontrol, because it has the potential to be sustainable over many seasons under favourable conditions.Suppressive soil is an example where the microflora in the soil is effective in protecting plants against soil-borne pathogens. The diversity and density of populations (bacteria, actinomycetes and fungi) is higher in suppressive soil than in conducive soil, including the diversity and population density of antagonistic microbes, for example in banana plant habitats without symptoms of Fusarium wilt (suppressive soil) is higher than the diversity of soil microbes in banana plant habitat with Fusarium wilt symptoms (conducive soil).