The Hidden Value of Mycorrhizal Fungi: How Many Species Does Your Garden Need?
Do you grow cannabis? Is your cannabis struggling to grow because of harsh weather and soil conditions?
According to research, the number of terrestrial plants that have a symbiotic association with mycorrhizal fungi is almost 80%.
One of the best things about gardening, in addition to creating lovely landscapes and growing healthy, delicious food, is that you learn many new things about plants and soil every day.
Over the past few decades, there has been some interest in identifying and understanding how beneficial soil organisms work. Research has shown that a lot of bacteria and fungi can help plants to combat diseases, obtain nutrients, and get water when there is a water shortage.
A complex group of fungi forms part of these beneficial organisms, known as Mycorrhizae.
To know more about Mycorrhizae and understand its value in soil, we will discuss 5 points:
- What does the term “Mycorrhizae” mean?
- Types of mycorrhizal fungi
- Are mycorrhizal fungi important?
- How many Mycorrhizal fungi species do you need?
- Bonus Tip: Steps to increase the population of mycorrhizal fungi
- Who benefits from mycorrhizal fungi?
What Does The Term “Mycorrhizae” Mean?
The term “Mycorrhizae” is literally translated to mean “fungus-root.” Generally, Mycorrhiza (singular) is a mutually beneficial relationship between a plant's root, the fungus colonizing the plant root, and soil factors. Mycorrhizae are fungi that often grow inside the roots or on the root surfaces of many plants.
This mutually beneficial relationship between the plant and the fungus involves the fungus facilitating the uptake of water and nutrients in the plant, while the plant takes advantage of photosynthesis to provide food and nutrients to the fungus.
According to plant physiology, evolution, and ecology, this exchange plays a significant role in the nutrient cycle.
Is there ever a time when this relationship is not beneficial?
Yes. The relationship between the plant’s roots and the fungus isn’t always mutually beneficial as the fungus tends to be slightly harmful to the plant. In some cases, the plant might also feed on the fungus.
It is also important to note that mycorrhizal associations do not apply to all plants, especially those that grow in nutrient-rich and water-logged soil. Plants that grow in such an environment can flourish without the assistance of mycorrhizal fungi. It is unlikely that you will find mycorrhizal fungi germinating in such an environment.
Types of Mycorrhizae Fungi
Mycorrhizae are made of predominantly two types, classified based on the colonization location of the fungi in the plants.
They are:
- Ectomycorrhizae
- Endomycorrhizae
- Ectomycorrhizae
Ectomycorrhiza favors woody plants when forming mutually symbiotic relationships. Examples of these plants are beech, fir, willow, spruce, birch, oak, and pine.
Ectomycorrhizal relationships always contain a Hartig Net. This is an intercellular surface consisting of highly branched hyphae that connect the epidermal root cells to the cortical root cells.
Another way to identify ectomycorrhiza is in the way it forms a dense hyphal sheath around the root’s surface, called the mantle.
So, ectomycorrhiza only lives on the outside of a plant’s root and can be found on only 5% to 10% of terrestrial plant species.
Examples of ectomycorrhizal fungi include:
- Laccaria bicolor
- Laccaria laccata
- Pisolithus tinctorius
- Scleroderma cepa
- Scleroderma citrinum
- Suillus granulatus
- Rhizopogon amylopogon
- Rhizopogon fulvigleba
- Rhizopogon luteolus
- Rhizopogon villosulus
- Endomycorrhizae
Endomycorrhizae can be found in more than 80% of extant plant species. These include greenhouse plants and crops, such as fruit trees, flowers, grasses, and most vegetables.
The relationship between endomycorrhizal plants involves fungi penetrating the cortical cells and forming arbuscules and vesicles. Simply put, endomycorrhizal relationships are very invasive.
In this relationship, there is an exchange mechanism inside the endomycorrhiza’s root, while the hyphae of the fungi extend outside of the same root.
Here are some examples of endomycorrhizal fungi:
- Gigaspora margarita
- Glomus aggregatum
- Glomus clarum
- Glomus deserticola
- Glomus etunicatum
- Glomus intraradices (AKA Rhizophagus irregularis)
- Glomus monosporum
- Glomus mosseae
- Paraglomus brasilianum
The four major types of endomycorrhiza include:
- Arbuscular Mycorrhizae: These mycorrhizae species are the most widespread and are popular for their high nutrient uptake and high affinity for phosphorus. They form arbuscules and ensure that fungi do not grow without their plant host.
- Ericaceous Mycorrhizae: Generally, ericaceous mycorrhiza is found on plants in acidic, inhospitable environments that fall under the order Ericales. Although they penetrate and invaginate root cells, they do not form arbuscules. However, they help the plants to regulate their acquisition of minerals like iron, aluminum, and manganese. They also form hyphal coils on the outside of the root cells, boosting the root volume.
- Arbutoid Mycorrhizae: They resemble ectomycorrhizal fungi. The fungal sheath they form encompasses the plant’s roots, while the hyphae penetrate the roots’ cortical cells to differentiate it from ectomycorrhizal fungi.
- Orchidaceous Mycorrhizae: Some orchids are non-photosynthetic, while others do not photosynthesize before the seedling stage. However, all orchids rely on sugars from their fungal partner for some time.
- This fungal invasion is required for germination because the seedlings cannot independently acquire sufficient nutrients to grow.
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In this relationship, the orchid parasitizes the fungus when it invades its roots. Then the seed coat ruptures, roots start to emerge, and the hyphae penetrate the root cells. This, in turn, creates hyphal coils, also called pelotons, in which a nutrient exchange takes place.
Are Mycorrhizae Fungi Important?
Are you still wondering whether your garden needs mycorrhizae fungi to thrive?
Check out these important reasons why mycorrhizae fungi are important:
- Mycorrhizae is nature’s gift to mankind as it sustainably addresses the constraints of improved quality productivity.
- Some mycorrhizal-obligated plants won’t survive to maturity without a fungal associate. Some of these plants are found in western North America and include bitterbrush, sagebrush, and some indigenous bunchgrasses.
- It is the only fungal system in the biofertilizer category.
- It is a non-specific organism with a broad spectrum.
- Also, it increases the photosynthesis rate to improve the growth, productivity, and yield of plants.
- Its ecological adaptability is broad, allowing it to grow in inhospitable habitats, such as deserts, tropical environments, the arctic, and adverse temperature regions.
- Mycorrhizae reduces the need for chemical fertilizers by up to 50%.
- Additionally, it speeds up the intake of vital nutrients (phosphorus and nitrogen) and immobile trace elements to improve plant nutrition.
- It also offers tolerance against various forms of soil stresses (such as salinity, heavy metal toxicity, high soil temperatures, and drought) to improve the plant’s chances of survival.
- It restores land productivity by helping to stabilize the soil structure and conserving the soil.
- It serves as a potential agent of disease control by offering higher resistance to many pathogens in the soil and roots.
The Value of Mycorrhizae Fungi
Mycorrhizae fungi are invaluable and come with immense benefits. For easier understanding, we have grouped the main benefits under 5 headings:
- Benefits to the soil
- Benefits to the plant
- Benefits to the grower
- Benefits to the end-user
- Benefits to the Soil structure
Soil structure refers to pore spaces and soil particle aggregation. Its maintenance is crucial to preserve the functions and fertility of the soil.
Do you own an intensely farmed land that has had its topsoil stripped away, such as a garden?
Then you have a lot to benefit from endomycorrhizal fungi. The chemical fertilizer applications combined with little or no organic matter replenishment must have left your soils without beneficial organisms.
Mycorrhizal fungi are vital in soil aggregation as it helps to produce hyphae networking and glomalin. Their presence helps to maintain the physical properties of the soil, leading to a better soil structure.
The effect of mycorrhizal fungi on the soil structure include:
- Increase in water holding capacity and water infiltration;
- Improved root development;
- Increased permeability to air;
- Greater resistance to compaction;
- Higher nutrient cycling and microbial activity;
- Improved resistance to surface sealing or crusts;
- Increased resistance to wind and water erosion;
- Benefits to the Plant
If you live or own a garden in areas where the soil lacks adequate amounts of nitrogen and phosphorus, you should expect to benefit tremendously from mycorrhiza associations. You could also benefit from this association if you stay in areas experiencing water scarcity.
This is possible because of the fine and small diameter of mycorrhizal mycelia, compared to the roots and root hairs. Hence, they act as another set of roots by increasing the surface area to allow easy absorption of water, nitrogen, amino acids, and phosphorus.
Because of the essential nature of these nutrients for plant growth, plants with mycorrhizal associations usually connect with non-mycorrhizal plants that depend solely on their roots for nutrients and materials.
Can plants survive without mycorrhiza?
If your plants do not have mycorrhiza, they will quickly succumb to the competition. Also, the plant composition in your garden or farm will change. This is worse for plants cultivated in stressful growing environments, such as arid conditions, low nutrient soils, unseasonal temperatures, excessive fertilizer, new plantings, and transplanting shock.
- Benefits to the Grower
Using soilless growing media containing endomycorrhizae usually cater to the plants’ fertility and watering needs, so they see fewer benefits. However, endomycorrhizal fungi help plants to endure adverse conditions and delay symptoms associated with stress that impacts crops.
If you are a commercial grower or landscaper, you will enjoy the following benefits:
- You will start noticing improvements in plant health a few weeks after application.
- Plants will look fresher and healthier which will lead to improved retail value.
- People buying your plants will enjoy an improved garden performance, yield, and more sales.
Here are some other grower benefits:
- Delays the wilting process: When plant roots cannot easily access water, endomycorrhizae transports water from the growing medium to delay wilting caused by water stress.
- Benefits to the End-User
Typically, cannabis growers have to consider more variables when they grow these plants outdoors. These variables, which include weather, soil quality, watering, and fertilization, may introduce more plant stress and increase the benefits of endomycorrhizal fungi.
Although endomycorrhizae can be directly incorporated into the soil, the roots of the plant will still be colonized even after the plant has been transplanted into the soil and is colonized inside the growing medium.
In addition to the benefits to the grower, the homeowner and landscaper also enjoy the following benefits:
Plants grown with endomycorrhizal fungi, especially in low fertility, poor quality soils, are often very large.
How Many Mycorrhizal Fungi Species Do You Need?
One myth you should not pay attention to is that you only need a single species of mycorrhizae or bacteria. Nature is extremely diverse. Having biological diversity ensures the plant has what it needs to thrive.
Has this myth misled you and prevented you from enjoying the benefits of biodiversity?
Biodiversity is crucial to the health of any ecosystem. Adding mycorrhizal fungi as beneficial symbiotic organisms during your growing practices helps to build a healthy ecosystem for the plants within the rhizosphere of the growing media.
Therefore, when you select products containing a higher number of species of either endomycorrhizal fungi, ectomycorrhizal fungi, or both, your plants will enjoy greater benefits throughout their life cycles.
According to research, mycorrhizae’s diversity in the root system of plants is important because the different species of mycorrhizae offer different benefits to the plant in varying circumstances and varying seasons.
For example, some species offer the plant more support regarding water efficiency, while others assist with nutrient uptake. Yet others prevent salts and toxins from reaching the vascular system of the plants. Most vascular plants are mycorrhizal, with 72% being arbuscular mycorrhizal (AM).
Also, some species are more active during the growing season, while others are more prominent during the warmer/drier months. Some species provide benefits in the winter or when the growing season is coming to an end.
Therefore, we advise that you choose products with greater diversity. The endomycorrhizal products should contain at least 4 species and the ectomycorrhizal products should have at least 7 species.
This will help you to maintain an ideal soil microbiome during your growing, landscape installation, maintenance, arbor care, or restoration project.
Bonus Tip:
To increase the population of mycorrhizal fungi:
- Increase aeration
- Increase the beneficial bacteria
- Apply mulch
- Do not disturb the soil
Who Benefits from Mycorrhizal Fungi?
Hopefully, at this point, you realize that incorporating mycorrhizae fungi into your production protocol comes with numerous potential benefits to you.
Are you a landscape architect, installer, maintenance worker, professional horticulturist, greenhouse/nursery grower, or homeowner who grows cannabis?
You can utilize this technology for successful restoration and reforestation projects.
If, however, you want to know more about Mycorrhizae, where to get it, and how it can benefit your garden, please contact us.