practical question about the use of spore products.

Welcome peter,
I currently use a product that contains spore mass of the following:

Endomycorrhizal fungi

Glomus intraradices, Glomus mosseae, Glomus aggregatum, Glomus monosporum, Glomus clarum, Glomus deserticola, Gigaspora margarita, Gigaspora etunicatum, Paraglomus brasilianum

Ectomycorrhizal fungi

Laccaria bicolor, Laccaria laccata, Pisolithus tinctorius, Rhizopogon villosullus, Rhizopogon luteolus, Rhizopogon amylopogon, Rhizopogon fulvigleba, Scleroderma cepa, Scleroderma citrinum, Suillus granulatus

Biological Disease Control Organisms

Trichoderma harzianum, Trichoderma konigii

Beneficial Bacteria

Azotobacter chroococcum, Bacillus azotoformans, Bacillus coagulans, Bacillus licheniformis, Bacillus megaterium, Bacillus pumilis, Bacillus thuringiensis, Paenibacillus durum, Paenibacillus polymyxa, Pseudomonas aureofaceans, Pseudomonas fluorescense

Currently I use it by inoculating seedlings at transplant time and soaking the holes I transplant them into, under the assumption that the symbiotic nature of these organisms will mean they spread after a few seasons as the soil recovers. Is this right? Or should I continue indefinitely? Or is there a tipping point related to soil carbon %?

I can see benefits now as I have done controls against plants without inoculation. But not sure how long I need to keep this up.

Hi Scott,

This is right, however the challenge with getting mycorrhizal relationships to form is that you cannot over fertilize the plant as it will thereafter choose to not to associate with the fungus. The exact tipping point of this is hard to measure but it is largely based on phosphorus and nitrogen inputs. Too much of either and the relationship will not form or, if established, stop.

Once it is established, future inoculations should not be needed.

Cheers
Peter

Peter McCoy wrote:Hi Scott,

This is right, however the challenge with getting mycorrhizal relationships to form is that you cannot over fertilize the plant as it will thereafter choose to not to associate with the fungus. The exact tipping point of this is hard to measure but it is largely based on phosphorus and nitrogen inputs. Too much of either and the relationship will not form or, if established, stop.

Once it is established, future inoculations should not be needed.

Cheers
Peter

Thanks for your prompt and helpful reply. My strategy for fertiliser is a bit more complicated. I don't fertilise the whole field at all. I simply mow a perennial living mulch cover crop that is between each row of crop. It is mostly grasses, but has probably an estimated 10-20 different species of grasses and forbs. I also plant companion annual species of herbs and covers in each row between my crop plants. I am going for the most possible biodiversity I can manage. Any more biodiversity and I believe I couldn't manage my crop.

But I do actually fertilise that initial transplant hole at the time of transplant. Besides the inoculant I also use a mixture of compost, compost tea, Espoma Organic Garden-tone, molasses, peat, and that spore product mentioned above. (and sometimes a bit of fish emulsion) Once this initial transplant and fertilization is done which is ONLY in the transplant hole, no further fertilization the rest of the season. I am planning to even eliminate the fertilization too, once my degraded soils recover.

Do you think that this fertilization strategy will also cause the mycorrhizae to not associate with my crop? Or reduce its effectiveness?

I am also going for the most possible biodiversity I can manage. For now, we have used endomycorrhizal, Trichoderma harzianum t-22 and Bacillus subtilis.