I know this only remotely goes to your question but I am growing my first tomato using mycorrhizal, and it's the first time that I don't have roots extending out the growing pot. I'll be interested to examine the roots when I'm done with this plant to see if they are more fuzzy like the mycorrhizal salesman said they would be.

Alan, I believe root mass has a direct relationship with it's green mass and an indirect relationship to nutrient levels.

Walt, are you using a hydro setup with your mycorrhizal fungi?

Hank, yes I am at 5 ml per gal of EA and EN. Worms Way recommended it for more efficient root growth. They said it would make the roots grow out from the sides as opposed to more linear growth. I've only been using it for about eight weeks. At least it's not hurting anything so far. And, like I said, there's no visible roots yet which is unprecedented for my experience. Usually I'm clipping roots every couple of days.

I've wondered about the effectiveness of mycorrhizal fungi in a hydroponic environment using inorganic nutrients. Another issue was how well the MF would thrive in a flood and drain system or other root submerged method. I would very much like to hear your thoughts on this. EA (EARTH AMBROSIA) and EN (EARTH NECTOR) seems like a convenient way of introducing MF into a hydro system. There is not much discussion on MF in this forum so if you could start a new thread on your observations using MF that would be very valuable information for our members.

Hank

actually its related to dissolved oxygen levels.

leaves need co2

roots need oxygen

get your bubbling bucket frothing at the surface and you'll have big giant rootballs.

This is a complex question that involves quite a bit of chemistry. "The effectiveness of mycorrhizal fungi in a hydroponic environment using inorganic nutrients." YIKES!!! 1)I just took a look @ the EA/EN, looks to me to be 1 part microbes with 1 part activator. Prob works well, but all of that sugar is going to gunk up
2)High salt ppm or peroxide/bleach use will kill the microbes
3)Microbe colonies might not like that much agitation, so no frothy water, try NFT or a seperate bio-reactor.
3)Contrary to what most believe air pumps do not add up to all that much DO. They stir surface water to fold in the air. Thus, where most people get lost is the most basic part... ie surface area of the bucket or tub pi r^2 vs lxw (*greater DO in NFT than bubblers guys...surface area). You CAN raise DO under pressure (*a pressurized tank or water column)
4)The microbe population is related to the sugar content @ the roots. In soil, this is a buffered, continual process of exchange. In water, there are no aminos and no sugars, so they must be continually added, or your colony may die.

This answer could have been 20 pages if I wanted, but I hope that this works.

I think a bubbler can significantly contribute to the DO (dissolved oxygen) in a container under the right conditions. If the container is a bottle say with a small neck the total surface area of an average bubble times the number of bubbles could be a large proportion of the exposed water surface area.
The table below shows what I mean. The shaded cells are surface areas in sq. cm.

As an example, a stream of 500 bubbles 2mm in radius would have a total surface area of 251 sq. cm. A sheet of letterhead is about 600 sq. cm.
Need to keep in mind the bubbles are moving which is equivalent to blowing air on the surface of the water.