SOIL DILUTION PLATE
(Image from MycoAlbum CD by George Barron see www.mycographics.com)
Make a suspension of soil in water and then dilute it to about 1/1000. Plate one ml of soil suspension onto a 7-day-old Rose Bengal agar plate. Incubate at room temperature for 7-10 days. On this plate you can see Alternaria, Penicillium, Cladosporium, yeasts and bacteria etc. It helps to control the bacteria if you add streptomycin at 30ug/ml to the RBA just before you pour the plates.