The Secret Lives of Fungi

by Kelly Ran

“Which is better: to have fun with fungi or to have Idiocy with ideology, to have wars because of words, to have tomorrow’s misdeeds out of yesterday’s miscreeds?”
-Aldous Huxley

When we tread on the earth, our feet alight upon soil that contains miles and miles of stringy networks. These clouds of mycelia, the underground components of fungi, spread under us like ethereal friends. Mycelia, which act as the “roots” of fungi, have coexisted with animals and plants since the beginning of our biological kingdoms’ existences (Azcon 96). Performing both beneficial and harmful tasks, mycelia enable growth and death in organic matter. Some fungi form symbiotic relationships with plants, allowing them to use nutrients in the soil that would otherwise be locked into the earth. Other fungi digest and decompose organic material, turning twigs and leaves into rich, dark humus, the nutritious matter that is part of soil.  For these two reasons, fungi exercise great power over the plant life cycle. The symbiotic relationship  of fungi and plants, called mycorrhiza, can be used in gardening and farming to improve plant growth and crop production (Stamets 50).  However, many conventional and organic farmers do not use fungi deliberately (i.e. they do not add fungi to their soil). Is fungus use scalable as an industrial farming soil improver, and is it a viable option in sustainable farming?

Sustainability Crisis

In the past decade or two, sustainability topics have been increasingly commonplace in food-related thought and actions. Most people are aware, to some extent, of our continued destruction of our limited resources.

Energy consumption and conversion is especially important because of their universality. Across all industries, cultures, and lifestyles, we consume energy when we power our manufacturing facilities, homes, and vehicles. Because many of our energy conversion processes pollute the environment, using energy means that we pay the price of smog-dense air, filthy water, and toxic soils.

Taking care of the soil plays an essential role in sustaining the Earth’s ability to provide for us. If we deplete soil of nutrients, we end up with inferior fruits, vegetables, and meats. Moreover, if we deplete soil, we must somehow improve the soil in order to resuscitate plant growth. More often than not, farmers throw excess amounts of artificial fertilizers on their lands. Not only do the fertilizers pollute the surrounding ecosystems, but their manufacture also creates pollution and energy problems.

Farmers also engage in monoculture, growing one or two crops on the same land year after year. Prone to diseases and pests due to the lack of diversity, the crops also require the same nutrients, so the soil becomes malnourished very quickly.

Of course, I have mentioned only a few of the unsustainable actions that we humans take. Many of these actions are intertwined, subtly linked  subversions that have complicated solutions. However, the issue of soil amendment and health may be answered with
symbiotic fungi.

Fungus Fundamentals

We may not think much about fungi, but most of us have benefited from different fungal species. The kingdom Fungi encompasses mushrooms, yeasts, and molds . Have you ever bitten into a wonderfully airy slice of bread or swallowed an antibiotic pill? If yes, then you have experienced the marvelous and mysterious ways of fungi, whose diverse members can cause thrush infections, induce hallucinations, create industrially useful
enzymes, ferment beer, poison animals, and rot buildings.

Mushrooms are actually the “fruit” bodies of certain fungi. Although plants and fungi are not perfect counterparts, we can use analogies to better understand fungal components: mycelium are like roots, and mushrooms are like fruits. Spores are like seeds.

In gardening and farming settings1, fungi help out in three main ways. Pathogenic fungi infect organisms with disease. Although these pathogens may seem harmful, we can harness their skills to our advantage by using species that target and kill pests. Saprophytic fungi perform the decomposition task that converts plant matter into soil. By decomposing this matter, fungi sequester nutrients into the soil and also break down toxins. The composting process accelerates drastically when beneficial fungi live in the compost  heap. Finally, mycorrhizal fungi live alongside plant roots. Known as mutualists, they take carbon from the plants in exchange for nutrients and water. Because mycelia (root-like structures) form thin strands, their surface area to volume ratio is quite high. Thus, they are able to absorb and deliver nutrients very well (Tugel 6).

In terms of soil improvement, decomposers and mutualists are most relevant. Cultivators sell them in various forms for farm and garden use. Growers can mix inoculant pellets into their soil, spray soil with water in which inoculant has been dissolved, or plant seeds that have been coated with a hard inoculant shell.

Mutualists have enjoyed recent popularity within specialty growers’ groups. For instance, journalist Shane Kavanaugh writes that many 1,000-lb pumpkins have sprung up from mycelinated soil (1). This year, the world record holder for the largest pumpkin, Chris Stevens, used Pumpkin Pro, a mycorrhizal fungal inoculant, saying “I don’t use Miracle-Gro, I use microorganisms” (Kavanaugh 1).

Home gardeners also use mutualists to increase crop yield and to grow bountiful flowers. Paul Stamets, a prolific researcher, cultivator, and supplier of fungi, has found that using mycorrhizal plugs in soil can increase plant growth drastically (230).

As useful as fungi can be, there are certainly limitations on how we can use them. Mycorrhizal fungi can proliferate wildly underground as long as they can find host plant roots. However, in laboratories, they require meticulous care in order to survive. This laboratory effect was known as early as 1989, when Marcia Wood noted the difficulty of propagating fungi in labs (11). Stamets has also written of the reluctance of mycorrhizal fungi to grow in artificial environments (428). 

The Winter of our Discontent

In natural environments, soil contains a plethora of microorganisms, including fungi and bacteria.  According to Arlene Tugel, a soil microbiology expert, more than 100 million bacteria reside in a single teaspoon of soil (2).  All of these fungi, bacteria, algae, and other organisms contribute to the overall health and activity of the surrounding soil and plants. By digesting plant material, limiting pest populations, and enabling nutrient use, soil microorganisms greatly improve the quality of plants that we can grow (Tugel 1).

However, many farmers lose the myriad benefits of soil microorganisms when they practice conventional farming methods. For example, Driscoll, a major grower and distributor of berry fruits, routinely sterilized its soil for many years. Driscoll required a “system reset,” along with chemical fertilizers, because it grew only a few crops: strawberries, raspberries, and blackberries. This effective monoculture depleted the soil of their farms (Newcomb).

Aside from a problematic lack of diversity, this approach is harmful for two reasons. First, sterilizing the soil every year kills most microorganisms in the soil. Without even a chance to reproduce and flourish, the critters in the soil cannot replenish the essential nutrients and chemistry of the earth. The undernourished soil associated with sterilization also tends to erode easily. Secondly, because the soil lacked humus and nutrients, Driscoll needed to use fertilizers. Not only do conventional fertilizers inhibit the microorganisms in the soil (Elstein 2004), but they also contribute to many related problems.

Common fertilizers fortify soil with nitrogen, phosphorus, and potassium. Known as NPK after its element symbols, such synthetic fertilizer causes numerous issues that make sustainability impossible. By definition, these chemical fertilizers must be synthesized in laboratories. The process of creating NPK fertilizer consumes energy in manufacturing plants and creates unwanted byproducts.

Chemical fertilizers also damage the ecosystems that surround farm lands. For example, nitrogen-based fertilizers, applied to most corn crops in the US, wash away from farms with the rain. This runoff drains to wetlands and river mouths where it literally feeds hungry algae. The overfed algae proliferate into “blooms” and breathe deeply, taking oxygen away from the water. The lack of water-bound oxygen suffocates fish and other aquatic organisms, and the entire ecosystem suffers.  According to writer David Biello, algal blooms pose significant threats in most of the important US river deltas (1).

Additionally, soil microorganisms are capable of filtering out reasonable levels of fertilizer in a process called denitrification (Biello). However, they cannot perform this task if they don’t exist in the soil because of sterilization.

The sterilization/fertilization procedure creates the very same problems that it attempts to treat. Unsustainable and detrimental to the environment, this method still enjoys popularity within the agriculture industry. I have not been able to interview any conventional farmers yet, but I suspect that this method is widely used out of habit and availability.

It follows that encouraging mycorrhizae (symbiosis between fungi and plants) would never succeed in the  standard farming model. The annual destructive cycle of treating the soil with unbearable heat (to sterilize) and harsh chemical fertilizers would not allow baby fungi to grow.

Fortunately, we may see slow movement towards more wholesome, sustainable practices that are compatible with mycorrhizae. . Looking to improve berry yield, Driscoll consulted microbiologist Elaine Ingham and adopted an microorganism-based approach to farming (Newcomb). Many organic and “ecoganic” farmers use the same approach: stimulating the naturally occurring fauna of the soil results in sustainably grown, reasonably high-yielding crops.

Ecoganic farms follow most, if not all, of the guidelines that define organic farming. However, these farms are not certified organic. For instance, Potomac Valley Farm in Virginia is not certified organic because the certification requires tedious, time-consuming paperwork and documentation. During its years as an organic farm, Potomac Valley had to supply minute details about its crop production, says Hiu Newcomb, a lead farmer. She had to submit information that allowed one to trace the plot location of each tomato and cucumber that she sold.

With a microbial-based ecoganic concept, farmers end up reaping the benefits of mycorrhizae, though this effect is not necessarily intentional. For example, Newcomb says that she encourages microorganism growth in her soil. By periodically sending off soil samples to be assayed , she ensures that her soil contains active bacteria and fungi. However, she does not specifically support symbiotic fungus species.

Solutions

Not only are fungi useful as naturally-occuring organisms, but they also contain much promise as an added soil improver. When used hand-in-hand with a microbiology-based approach, they can increase soil productivity, crop yield, and overall ecology health without the use of synthetic fertilizers.

By inoculating soil and compost with a mix of mycorrhizal fungi, farmers can “plant the seeds” of healthy growth. Then, they can periodically assay their soil and add more fungi as needed.

However, the major roadblock to this solution is that most farmers have a destroy-replenish mindset. The norm in American industrial farming is to deplete to soil and then to inundate it with artificial fertilizers. The next big question is how we can encourage farmers to adopt sustainable methods. Only when sustainable farming is the norm can fungi truly thrive as farmers’ friends.

Currently, we can acclimate our society to the use of mycorrhizal fungi by increasing its use in home gardens. Increasing advertisements, media coverage, and accessibility in stores would raise fungi’s profile as well as inspire people to use fungi in their lawns, flower pots, and vegetable gardens. Once our society becomes more familiar with mycorrhizae-based soil amendments and their benefits, our political and cultural atmosphere will become more friendly to fungi use in industrial farming.

Perhaps if more Americans grow their own seasonal produce, they will better appreciate what it takes to farm quality food while keeping the Earth healthy. By trying to coax baby potatoes and crisp lettuce and sharp peppers from the soil, they might have a better understanding of what farmers do and how most of their food is produced. Furthermore, if people see how soil quality greatly affects produce yield and taste, they might place more emphasis on sustainable, wholesome farm practices.

From a cultural perspective, I would like to see our society encourage more ecoganic compromises: farm’s don’t have to be certified organic! I would be happy if conventional farms switched over to mostly organic practices. One reason why farmers don’t try organic farming is because their soil needs to be pesticide-free for a number of years before they are eligible for an organic certification. Because of this eligibility requirement, farmers would have to spend a few years converting their land to organic by stopping synthetic fertilizer use. During these years, they would not be able to claim organic status. If we, as a culture, demanded more ecoganic produce, then farmers wouldn’t feel as though their “in-between” period were wasted. Also, farmers wouldn’t feel pressured to deal with suffocating paperwork to get certified.

We also need increase science-based logical thinking in our media and government. To me, it seems very likely that our actions are unsustainable, in general. I think that the odds are obvious: making the effort to become sustainable takes relatively little cost compared to the likely risk of destroying the planet. We need to increase ecoganic-friendly benefits and legislature and encourage people to realize that sustainability is important.

When more farms stop using NPK chemicals, the rise of fungi will begin. Their use will be part of a holistic approach to farming that might decrease the chance of catastrophe.

Works Cited

Azcón-Aguilar, Concepción, et al. Mycorrhizas – Functional Processes and Ecological Impact. Springer-Verlag Berlin Heidelberg, 2009. Web. 10 November 2010.

Bielo, David. “Fertilizer Runoff Overwhelms Streams and Rivers.” Scientific American 14 Mar. 2008.

Brassley, Paul. “Fertilizing.” The Oxford Encyclopedia of Economic History. Ed. Ed Mokyr. Oxford University Press, 2003. Web. 11 November 2010.

Elstein, David.  “Soil Fungi: Plants’ Natural Friend. ” Agricultural Research  52.5 (2004): 7-7.  Research Library Core, ProQuest. Web.  9 Nov. 2010.

Kavanaugh, Shane. “From the Garden to the Record Books, a Supersize Pumpkin.” New York Times 19 Oct. 2010.

Newman, Hiu. Personal interview. 21 Nov. 2010.

Stamets, Paul. Mycelium Running: How Mushrooms can Help Save the World. 1st ed. New York, New York: Ten Speed Press, 2005. Print.

Tugel, Arlene, Ann Lewandowski, Deb Happe-vonArb, eds. 2000. Soil Biology Primer. Rev. ed. Ankeny, Iowa: Soil and Water Conservation Society.

van der Heijden, M., and T. Horton. “Socialism in soil? The importance of mycorrhizal fungal networks for facilitation in natural ecosystems. ” The Journal of Ecology  97.6 (2009): 1139. Sciences Module, ProQuest. Web.  11 Nov. 2010.

Wood, Marcia.  “Underground Allies of Plants. ” Agricultural Research  37.11 (1989): 10-13.  Research Library Core, ProQuest. Web.  11 Nov. 2010.


(1) I’d like to define the difference between gardening and farming. Both may produce crops, but only farmers are concerned with selling what they grow. Gardeners grow plants solely for personal consumption and enjoyment.

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