The science of mycorrhizal symbioses dates all the way back to the Enlightenment era, when the Frenchman, du Monceau made some highly important discoveries as to the nutrition of plants which, in today’s situation, may save the world from a global famine—which is predicted to occur within the middle of the present century.

Included in the French Encyclopedie (1751-72), du Monceaus novel scientific approach to plant growth were picked up by, among others, the Russian Kamenski in the 1880’s and elaborated on in the rather well known soil science of Selman Waksman, William A. Albrecht and Albert Howard in the early 20th century.(1) However, it was only towards the end of the 20th century that a huge breakthrough within this science was accomplished within academia, and started to be implemented within organic horticulture and agriculture in a highly advanced scientific manner.(2)

Today, when the world is running out of mineral phosphorus and climate change is threatening agricultural practices on a worldwide scale, the implementation of mycorrhizal symbiosis should be high on the agenda among organic horticulturalists and farmers around the world—urban as well as rural.

Based on scientific experiments with this kind of applied mycology during the past 20 years or so in southern parts of Norway, I will try to delineate in some short paragraphs how this innovating science may be applied in your gardens and in your fields. The main thing to remember is that, as always when it comes to ecological matters, diversity is a strength and a receipt for survival—in the world of plants as well as in the animal and human world.

So, if you are practicing some kind of plant cultivation—or are planning to do so in the future—here are some recommended practical steps to be taken:

Ideally, when you start a new garden or a new field for vegetable cultivation, in pre-season do the fallowing with some kind of soil cultivator (ideally electric) or horse or oxen drawn harrow, and then sow the field with some annual clover species—inoculated with rhizobium bacteria if there are no legumes in your field initially. In many lawns one will find white clover and in such cases inoculation with rhizobium is not necessary.

Then, next season, after mowing and molding down the green manuring clover in previous early autumn, divide your field into the several sections that you prefer in your crop rotation system (at least 4, but the more the better). In early spring, when nettles are sprouting almost everywhere, gather a reasonable amount of those herbs (depending on the area which you are cultivating—some 10-20 liters per 250 m2), and add it to some barrel or bucket of 20oC water, and start turning the content around once a day. This will turn into a greenish “nettle soup” within the next two weeks or so, providing a nitrogenous substrate in which to prepare the activation of the mycorrhizae spores—the gathering of which is the next preparing step to be taken to guarantee a successful growth season.

The gathering of mycorrhizae spores is easily done in the top soil area among wild plant communities along fences, roadsides and in the nearest forest areas, as close as possible to your garden or field—or at least within the same bioregion. Simply use a bottle or glass with a cap on and make several tiny holes in the lock to let oxygen into the container, and start gathering the widest diversity of soil samples—in the surface soil around healthy plant communities (trees as well as herbs, ideally belonging to the same plant community)—to provide for the greatest possible adaptability of the plant-mycorrhiza symbiosis that is obtainable in your area.

Then, when the growth season has started and your cultivated plants are large enough for the mulching (green manuring) process to begin, you start adding the nettle substrate with the mycorrhizae spores to your cultivated area. First, apply the mulching material (whether lawn cuttings or other grasses) to the plant rows and, in humid weather, add to the rows some wide sprays of your microbiological inoculum. Before spreading your substrate, make sure to add to it cold water (as cold as you can get) for some 5 to 10 seconds, and then increase the temperature quickly to about 20oC. This is to activate the sporulation process, that is, to see to it that the mycorrhizae spores start to grow hyphae that will subsequently hook on to your cultivated plant roots.

According to how large a yield you want to obtain from your crops, simply repeat this process throughout the season—after moulding down the green manure in the surface soil. Take care not to mold it in too deeply, so that the mycorrhizae hyphae don’t get disturbed between the plant roots. Reduce weeding to a minimum, as the so-called “weeds” only add to the desired diversity in your field, Basically, concentrate the weeding process on the period from sprouting to the first mulching and then just let it all grow!

Then, after probably harvesting your best yield ever, when the next season comes, without too much disturbance in your top soil layer, you already have established the mycorrhizal hyphae network in your soil. So, it can be advantageous just to prepare sow beds without harrowing your entire field. The kind of practice that you choose will naturally depend on how much perennial “weeds” have been accumulating during the previous season. If you plan to do the soil cultivator approach or the harrowing over your entire field, make sure to save some of your mycorrhiza substrate from the previous season, so that you can repeat the entire process. Maybe you could also add some new mycorrhizae species to your substrate to enrich the diversity even more. You should also see to it that your substrate is turned over once a day so that oxygen is let into it.

This kind of approach to organic horticulture and agriculture will enable gardeners and farmers to reclaim maltreated soils after one-sided cropping, chemical manuring and the use of pesticides, especially on heavy clay soils. Just let the “weeds” grow when nothing cultivated seems to thrive on the soil and mow it down on the surface two or three times during the growth season, and make sure to add the above mentioned mycorrhiza substrate after the mowing is done and in humid periods. The mineral strengthening of the plant roots resulting from the mycorrhizal symbiosis enables the plant roots to penetrate vastly deeper into the mineral soil, where dormant mycorrhizae spores may be activated during the process. In this way, micronutrients and phosphorus may be brought back to the top soil layer and re-fertilizing the fields in a most efficient manner. After a season or two with this kind of mulching process a new top soil layer should be created, in which to prepare for the mycorrhizal way of gardening and farming—ideally starting it all by sowing an annual or perennial legume crop such as Persian clover or red clover respectively.

Another asset of mycorrhizal cultivation is that the fungi function as detoxificating agents in the soil, cleaning away heavy metals and pesticide residues from industrial agriculture and its highly useless crops. But the mycorrhizae need soil organic matter to thrive on, and it needs a soil in which air and water can penetrate—that is why the meadow, whether leguminous or not, is so important in your crop rotation system. So, make sure that if you practice a 4 year crop rotation plan, you reserve one of those seasons to some kind of meadow crop (preferably one or several legumes), or two seasons if you practice a 8 year rotation system, and so on. Then in early autumn you mow and mould the green manure crop into the top soil, so that you abide by the “Law of Return” (to use Albert Howards expression) and allow for a perfect sow bed in that area in the following season.(3)

Utilizing this kind of gardening and farming, local communities will be far better enabled to munizipalize their basic economies as part of a libertarian municipalist campaign, and will be far less dependent upon foreign imports of necessary resources for farming. Remember, the soil is in the depth—not in the acres!

Notes:

1. Trappe & Castellano: Mycolit: 1758-1991; and S. E. Waksman, Principles of Soil Microbiology (London: Baillière, Tindall and Cox, 1932); Charles Walters. ed., The Albrecht Papers (Acres, USA, 1975); Albert Howard: Soil & Health (1947: Kentucky: University Press of Kentucky, 2006).

2. S. E. Smith & D. J. Read: Mycorrhizal Symbiosis (1983: New York: Academic Press, 2008); M. G. A. van der Hejden & I. R. Sanders, eds., Mycorrhizal Ecology (London: Springer Verlag, 2002); C. Hamel & C. Plenchette, eds., Mycorrhizae in Crop Production (New York: Haworth Food and Agricultural Products Press, 2007).

3. See also Atle Hesmyr, Efficient Gardening in the Northern Hemisphere: A Diary (2012: available at Scribd.com).