I helped a neighbor validate her above ground results correlating them to underground biological conditions. She was testing a control of sterilized potting soil with commercial and home made IMO inoculants and also the effectiveness of biochar in stimulating biological growth.
The above ground growth perfectly correlated with the soil biology. More growth = more biology.
We noticed the sample with biochar and IMO had the presence of amoebas, which help to eat the bacteria and make nutrients available in a plant available form. Also, the samples with char had active biology, where all the other samples all of the biology was inactive.
Great to know that the microscope backs up what we intuitively know. Better growth = better biology.