It looks like it would be very simple to do a side-by-side comparison with this system. Plant a couple passes with the exhaust hooked to the seeder fan and then unhook and plant with nothing but air. Have you done such?

When you say you are injecting the gas into the soil, does that mean that all the gas goes into the soil and none escapes. If that's so, why does it drop the seed? How deep are you injecting this gas? If it does indeed work, it looks like the guys that inject anhydrous could save a lot of fuel by just going shallow with an air seeder, instead of running the knives 6" deep or so. I am guessing that if you tried such with anhydrous, you'd see a lot of white vapor and smell a strong odor of ammonia.

I have never been much a fan of anecdotal evidence and testimonials. Do you remember when the merchants promoted using a ring of strong magnets around the tube of the drill fillers. Their theory was that treating the seed with a dose of magnetism would cause better germination and stronger seedlings. There was no shortage of guys that ponied up the $100 for the magnet and swore their crops were lots better because of the magnet treatment. Notice how no one sells or buys the magnetic rings anymore? Ever wonder why folks quit using them if they made that much better crops?