You don't - and you won't know that by using a microscope either. There are millions of species - even soil scientists have not identified most of them.
Thank you for sharing! microBIOMETER is an inexpensive tool for busy growers and farmers to obtain a quick snapshot in real-time of the biology in their soil to determine if their soil management efforts and amendments are working. Testing data is saved in the app by GPS location for future reference and analysis. For many, a microscope is not a workable solution due to cost, inexperience, accuracy and time restraints.