Microbes - Glomalin

I worked at a USDA research lab in a soil lab focusing on glomalin research.  My boss was part of the research group that discovered it!  Giving the mycorrhizal fungi a living root to live off of is one of the best benefits of cover crops!  My whole job was to find out exactly how much glomalin was in soil samples and how water stable the aggregates were.  Very, very general summary: cover crops during times a field would be fallow = more glomalin in the soil. More glomalin= more water stable  aggregates = less soil washing away or compacting during heavy rain.  Also better water retention was associated with more glomalin.

Basically the longer you have a living root in the soil the better from a mycorrhizal fungi and glomalin perspective.

Important to note, not all plants form a relationship with mycorrhizal fungi.  Not all living roots are created equal for this purpose.  Even some of our veggies are non mycorrhizal!  This makes crop rotation even more important! 

Some common crops that do not facilitate mycorrhizal growth include: all brassicas, ggoosefoots(beets, chard, amaranth, quinoa)  rhubarb, and even buckwheat. So while buckwheat is a great cover crop for managing reasons; if your goal is to provide a living root for the mycorrhizal fungi to live off of, then buckwheat is a poor choice.

Hopefully that info is useful. 

Interesting , do you know how does the pelleted form of mycorrhizal fungi crop enhancer fits into the picture .
 On the packet it says put a measure of the pellets down each planting hole , then plant you cabbages or other plants .
 
 I wasn't going to bother using at all it till I read of it being recommended by the ROYAL HORTICULTURAL SOCIETY .

 I trialled it this year on all sorts of plants & bare rooted cuttings once I realised that we were going to have a long cold wet summer . .  My legumes as expected had masses of nitrogen nodules all over them  so did some but not all of the cabbage & cauli roots I took out after the second crop of new baby cabbages & caulis .  In a few days time when I've harvested the final courgettes I'll find out how it's worked on them too . 

 My thinking about it is that high levels of the fungal spores will be present in the soil for many years as some of my ANSFG beds are getting on for six  years old and are rarely without any sort of crop in them .

plantoid wrote:Interesting , do you know how does the pelleted form of mycorrhizal fungi crop enhancer fits into the picture .
 On the packet it says put a measure of the pellets down each planting hole , then plant you cabbages or other plants .
 
 I wasn't going to bother using at all it till I read of it being recommended by the ROYAL HORTICULTURAL SOCIETY .

 I trialled it this year on all sorts of plants & bare rooted cuttings once I realised that we were going to have a long cold wet summer . .  My legumes as expected had masses of nitrogen nodules all over them  so did some but not all of the cabbage & cauli roots I took out after the second crop of new baby cabbages & caulis .  In a few days time when I've harvested the final courgettes I'll find out how it's worked on them too . 

 My thinking about it is that high levels of the fungal spores will be present in the soil for many years as some of my ANSFG beds are getting on for six  years old and are rarely without any sort of crop in them .

Firstly, while legumes do form a symbiotic bond to mycorrhizal fungi, they also form a symbiotic bond with rhizobium bacteria.  It is the rhizobium bacteria nodules you see in legume roots not mycorrhizal fungi.  It is also this bacteria that fixates atmospheric nitrogen that make legumes so amazing in crop rotations. 

Secondly, I'm rather surprised it would recommend inoculating with mycorrhizal fungi for cabbages or other brassicas as they do not form a relationship with mycorrhizal fungi.  The fungi cannot live on their roots.  In fact, there is some evidence brassicas produce a chemical that may be toxic to mycorrhizal fungi.  

But as long as you aren't growing solely brassicas in a bed, I agree you should have plenty of fungal spores.  The less you disturb the living roots of plants that do form that symbiotic relationship with mycorrhizal fungi the better, from a glomalin perspective at least.

Robbomb116 wrote:Important to note, not all plants form a relationship with mycorrhizal fungi.  Not all living roots are created equal for this purpose.  Even some of our veggies are non mycorrhizal!  This makes crop rotation even more important! 

Some common crops that do not facilitate mycorrhizal growth include: all brassicas, ggoosefoots(beets, chard, amaranth, quinoa)  rhubarb, and even buckwheat. So while buckwheat is a great cover crop for managing reasons; if your goal is to provide a living root for the mycorrhizal fungi to live off of, then buckwheat is a poor choice.

Hopefully that info is useful. 

Thanks for this info and the info above about glomalin.  Interesting.  I knew my planting a cover crop was helpful, but this gives me some ideas about which crop may be better.  I always grow buckwheat whenever I have an empty bed in the summer but I guess it is not the best choice.  But it grows so fast.  Do you have any other suggestions for the middle of the summer.

yolos wrote:

Robbomb116 wrote:Important to note, not all plants form a relationship with mycorrhizal fungi.  Not all living roots are created equal for this purpose.  Even some of our veggies are non mycorrhizal!  This makes crop rotation even more important! 

Some common crops that do not facilitate mycorrhizal growth include: all brassicas, ggoosefoots(beets, chard, amaranth, quinoa)  rhubarb, and even buckwheat. So while buckwheat is a great cover crop for managing reasons; if your goal is to provide a living root for the mycorrhizal fungi to live off of, then buckwheat is a poor choice.

Hopefully that info is useful. 

Thanks for this info and the info above about glomalin.  Interesting.  I knew my planting a cover crop was helpful, but this gives me some ideas about which crop may be better.  I always grow buckwheat whenever I have an empty bed in the summer but I guess it is not the best choice.  But it grows so fast.  Do you have any other suggestions for the middle of the summer.

Getting beyond my knowledge as an intern lab monkey.  Buckwheat is still good for many* (that's what I meant to say earlier, stupid autocorrect), just not really for mycorrhizalunch fungi.  

Not sure what a good cover crop for middle of summer that would benefit mycorrhizae.

yolos wrote:Thanks for this info and the info above about glomalin.  Interesting.  I knew my planting a cover crop was helpful, but this gives me some ideas about which crop may be better.  I always grow buckwheat whenever I have an empty bed in the summer but I guess it is not the best choice.  But it grows so fast.  Do you have any other suggestions for the middle of the summer.

After some reading on good hot weather cover crops and double checking the plant families to make sure they are mycorrhizal hosts, some good options might be sorghum-sudangrass or cowpea.  Again, buckwheat is still useful for other reasons si you don't have to completely stop using it.

Robbomb116 wrote:

yolos wrote:Thanks for this info and the info above about glomalin.  Interesting.  I knew my planting a cover crop was helpful, but this gives me some ideas about which crop may be better.  I always grow buckwheat whenever I have an empty bed in the summer but I guess it is not the best choice.  But it grows so fast.  Do you have any other suggestions for the middle of the summer.

After some reading on good hot weather cover crops and double checking the plant families to make sure they are mycorrhizal hosts, some good options might be sorghum-sudangrass or cowpea.  Again, buckwheat is still useful for other reasons si you don't have to completely stop using it.

Thanks Robb.  I use the buckwheat when I have a short growing period between crops.  In 30 days it grows from seed to flower in my climate.  I also grow cowpeas (Lady, White Acrea, Pinkeye Purple Hull) every summer for fresh cowpeas.  Then I chop off the tops (if not too infested with aphids) and compost them and leave the roots in the soil.

the excellent glomalin explanation posted by robbomb116 can be demonstrated in layman terms in the video below. please ignore the back to eden versus leaf mold title. He explaining in a visual way how the glomalin and micorrihizae work and formed our soil texture,aggregate. This explained why having a living plant root that will benefit from mycorrhizae is helpful.  
If you look at the list below, I highlighted what normally we may have in our garden. so I going to try mixing some of the plants around my plants like lettuce, scattered onion, if there not a companion problem. If the lettuce gets too big, i'll just cut it low, but keep it alive. so basically it will be a cover crop with a living root that allowing mycorrhizal to formed. So i'll have the compost, fungi/bacteria and the rest of the soil food web critters ,plus the living plants for mycorrhizal. 
In SFG we already have different plants in each 12" square. this process seem simple enough. 

since brassica, beets, kale and spinach don't respond to mycorrhizal, It be helpful to get the fungi/bacteria ratio up  for the falls crop to 300 fungi :600 bacteria, per Dr. Elaine Ingham.

What is recommended for those of use that literally follow Mel's SFG and have table top beds with 6-7" of Mel's Mix? Mix in a little mychorrhizae for winter and summer planting? If we make our own fungal-rich compost with leaves as a major ingredient, will that suffice?

PS: I appreciate when an existing thread is bumped instead of creating new ones. Some of the old ones are gems.

Thanks. I roughly mix new compost into the beds at change of crops (April and October). It sounds like you just top dress new compost. ??

sanderson wrote: It sounds like you just top dress new compost. ??

That's what I got out of it -- never mess with the soil. Period. Just add on.

Thank you for clarifying. I always roughly mix to keep the vermiculite incorporated throughout.