Why you need it in your soil.

http://articles.mercola.com/si...

Not all plants need or rely on Mycorrhizal fungi; there are Nonmycorrhizal plants that have alternative nutrition uptake mechanisms.
http://mycorrhizas.info/nmplan...

KD, that seems to say that the entire Brassicaceae/Cruciferae family is mostly nonmycorrhizal!
That comes as a surprise!

"No arbuscules observed in 649 taxa inoculated with a VAM fungus, but 19% had hyphae and vesicles (DeMars & Boerner 1996). Some literature reports suggest VAM occurs occasionally, but most found NM roots only..."

I wonder if they've tried a wide variety of MR species on Brassicas.

And I've read that roots usually don't accept MR unless they are having trouble getting enough water and/or phosphorous. If the tests are done with well-watered, fertile soil, they would not have seen many roots with arbuscules.

But hopefully and presumably they know their own field better than I do!

PSU says:
"Crops incapable of forming mycorrhizas (canola, buckwheat, forage radish, camelina, mustards) inhibit mycorrhizal fungi."
http://extension.psu.edu/plant...


"Nearly all crop plants can form AM associations except lupins and brassicas such as canola."
http://www.soilquality.org.au/...

Learn something new every day! Thanks!

You're welcome, Rick. Yes, this info is good to know as I would not want to waste my money buying and incorporating mycorrhizal into soil of those plants that do not need it.

It tells me that I had better inter-plant something other than Brassicas, or rotate with crops other than Brassicas, in my beds or there won't be many MR spores in my beds!

Very interesting read(s). Do you all rotate brassicas normally? I've grown kale in the same spot for the past couple of years.

My guess would be that the kale and other Brassicas would continue to do OK.

But when you do plant something else there, maybe it would be a good idea to add some soil from another bed into the planting row. To increase the number of MR spores.

Thanks, Rick. I did have beautiful kale this year and would hate to move it. It does grow at the foot of my tomatoes though (which I never rotate due to extreme lack of space). Do you think that would interfere with the tomato roots?

I'm just guessing, but I wouldn't think that would be a problem. The tomatoes would probably keep the level of MR spores high in their spot, so it wouldn't matter if there were few spores "next door" in the kale patch.

If you till heavily, I wouldn't expect the "dilution" of spores to hurt the tomatoes any. Since they multiply once they connect to roots and invade them, the tomatoes probably only need enough spores to "inoculate" them.

I think I've seen reports that roots acquire fewer MR when there are few spores in the soil, but I wouldn't think that "diluting" them by tilling and mixing the tomato's soil with the kale's soil.

I WOULD worry if articles were saying that one kind of MR competes with or suppresses another. But I never heard that.

I wish someone who knows more about it would chime in!

Yeah, I guess I do "till" to work in stuff like egg shells or organic fertilizer.

If the spores really are only an inoculum, that should keep your kale area supplied with spores. And any weed seedlings would pick them up and multiply them.

(What I've said in this thread is just my belief, not things I've seen directly supported in print.)

I think some mixing and re-aerating soil is a good thing, but I have only worked with heavy clay soils and most of my beds are still pretty heavy and tend to "settle".

Soil - same here. I have what's called Miami soil - clay with sandy loam on top. If I don't mulch (with shredded leaves), the top of the soil can get crusty and compacts easily even though I avoid stepping in the beds as much as possible.

Mulch is good for many reasons!

Do you ever scrape up some of the underlying clay, break it up, and mix it with your sandy loam to get better water and mineral retention in the top layer?

In my soil, that requires a lot of screening to pull out all the hard little "clay balls", but eventually the clay mixes with the looser soil or amendments.

I have dug amendments into that soil in the past but it seems like I would have to do it consistently as the benefits tend to decline over time. I'm thinking of adding some gypsum in the spring but need to find time to assess my soil test results first. My one veggie bed is a hodgepodge of bulbs, shrubs and perennials along with space for a few veggies so major soil amending is tricky.
Has anyone ever tried "liquid" gypsum?

Shadegardener said:I have dug amendments into that soil in the past but it seems like I would have to do it consistently as the benefits tend to decline over time.

It helps if some of the amendments aren't organic, like crushed stone, grit, very coarse sand or possibly Perlite. Compost is digested very quickly. Bark lasts longer, and coarse coir fiber seemed to last longer. But grit is forever!

Even then, the "loft" or air spaces tend to settle or slump and fill up with clay and silt.. That's why I turn deeply every few years, at least in the beds that are still very heavy and clay-ey. I try to "whip up" the soil like whisking air into an omelet. A broadfork does for top few inches what I try to do more deeply by turning and forking.

I used to dig in the previous years' wood mulch but I don't mulch with wood chips anymore - just shredded leaves. While I've disliked the look of perlite in garden soil, I did add some to a section where I experimented with carrots this year. 'Danvers Half-Long' got to 5 inches long.
Speaking of forking (and I know I'm waaay OT), has anyone seen a very narrow turning fork? With all of my established perennials and shrubs, I could sure use one.

Shadegardener said:I used to dig in the previous years' wood mulch but I don't mulch with wood chips anymore - just shredded leaves.

Since I "poisoned" one bed by turning a lot of woody stuff under one year, I never do that. It grew a fine crop of ugly white, duty, hydrophobic fungus, and NOTHING else. Woody mulch: yes. Turn wood under? No. Hugelculture is different, wood UNDER the main root zone wouldn't bother me.

Shadegardener said: While I've disliked the look of perlite in garden soil,

ME, TOO! It makes my bed look like I'm growing pot, to my eyes. I like grit or crushed rock.

Shadegardener said: Speaking of forking (and I know I'm waaay OT), has anyone seen a very narrow turning fork? With all of my established perennials and shrubs, I could sure use one.

I never saw a narrow garden fork. For that kind of thing, i use my favorite "Sharpshooter" spade, or trenching spade. Long, narrow blade.

I do have a trenching spade that I use for digging up perennials or shrubs in tight spaces but the "blade" is very long and makes it a little awkward for aerating the soil. I do like the length for digging up plants though.

>> awkward for aerating the soil

I agree. But good for deep turning without double-ditching.