by, 06-24-2011 at 12:22 AM (898 Views)
I want to introduce you to Robby, a horticulturalists for a company the makes a popular USB plant sensor. He has a heavy ecological background in local and native plants. I've had the pleasure of talking to him on several occasions about general gardening. I want to share a few of our conversations you with starting with his letter on Beneficial Microorganisms. I hope you find this information useful.
Me, "Hey Robbi, what can you tell me about mycorrhizae & ectomycorrhizae? I hear they help the roots absorb more nutrients and fight diseases. What are your thoughts?"
Robby, "Mycorrhizae are fungi that form a symbiotic relationship with many, many plants. There are three main types: Ericoid mycorrhyzae, endo-, and ectomycorrhizae. Ecologically speaking, a mutualistic relationship means that both parties will benefit. In this case the fungi will get sugars from the plant and the plant will get more nutrients (usually phosphorus) from the fungi.
These fungi associate themselves with the plants roots and will essentially increase the surface area that the roots are exposed to the soil. In addition, the fungi have a few tricks up their sleeves to make nutrients more available for absorption.
You can inoculate your soil with these fungal spores, but they more or less are found naturally in nature. Many plants cannot thrive without them now. In fact acid rain has a detrimental effect on the growth and infection rate of these mycorrhizae and many scientists feel that trees suffer more from lack of mycorrhizal infection than from the acid rain itself.
Now here's the kicker: plants are sacrificing some sugars to the fungi for the fungal services, but what happens if the nutrients are not in any deficiency in the soil. In other words, what if you as the gardener are capable of constantly providing enough nutrients to the soil so that the plant is never really lacking.
In this scenario, a plant that has a mutualistic relationship with a mycorrhizal fungus is now sacrificing sugar that could be used to make new plant parts to the fungus for no added benefit. This is generally the case for plants grown in pots.
Mycorrhizal fungi will give the greatest benefit to plants living in the ground and not in pots. This makes sense when you think about it though. The mycorrhizae help the plant explore the soil for nutrients. When a plant is in a pot, the roots cannot really explore much and the nutrients generally have to be provided to them.
I hope this is helpful. Let me know if you have any further questions.
- Dr. Robby"