Below are my pictures of a tray of diakon radish grown on coconut coir mat for the first time for me. One ounce of seed was sprinkled on a mat soaked in H2O2 and covered with vermiculite, uncovered and under lights 5 days later and harvested another 5 days later. Yield is 8.5 ounces. (first 3 pictures)
In October I dry seeded one ounce of diakon radish seed on soil and covered it with soil. It was uncovered 3 days later, harvested 6 days after that, and the yield was nearly 16 ounces. (4th picture)
Now conclusions should not be drawn from just one or two data points, but I believe there might be a lesson in here that the nutrients in the organic soil mix may produce a larger yield. The experiments will continue. There are still some advantages in growing with a non-soil grow medium (mainly that live plants are more kitchen friendly if there is no soil) but yield is obviously an important part of the equation.