Written by Asma Johansson and Molly Callaghan
What Are Mycorrhizae?
Mycorrhizae are symbiotic associations that form between the roots of most plant species and fungi. The term Mycorrhiza literally means “fungus root” and was first described by a German forest pathologist in 1885. It was estimated that 95% of all plant species belong to the genera that form Mycorrhizae. Little things run the world and this is especially true when it comes to getting plants established. Under natural conditions, plants live in close association with Mycorrhizae. Estimates of mycorrhizal filaments present in healthy soil are astonishing. Several kilometres of filaments can be present in less than a thimbleful of soil associated with growing plants. The hyphae act as a link between the roots and the soil to increase nutrient uptake.
How do Mycorrhizal Fungi work?
Mycorrhizal root systems increase the absorbing area of roots 10 to 1000 times thereby greatly improving the ability of the plants to utilise the soil resources. Mycorrhizal fungi are able to absorb and transfer all of the 15 major macro and micro nutrients required for plant growth. Mycorrhizal fungi release powerful chemicals into the soil that dissolve hard to capture nutrients such as Phosphorous. This extraction process is particularly important in plant nutrition and explains why non mycorrhizal plants require higher levels of fertility to maintain their health.
Mycorrhizal fungi form an intricate web that captures and assimilates nutrients from the soil to the root. They are also involved in a wide variety of other activities that benefit plant establishment and growth. The same web of fungi is very important for water uptake and storage. In non-irrigated conditions, plants inoculated with mycorrhizae are under far less drought stress compared to untreated plants.
Mycorrhizal fungi also improve soil structure. The intricate web of hyphae produced by these organisms also produces humic compounds and “glomalin” which is a soil glue. This glue binds soils into aggregates and improves soil porosity. In sandy or compacted soils, the ability of mycorrhizal fungi to promote soil structure is of great importance.
Advantages of Mycorrhizal Fungi
The benefits afforded plants from mycorrhizal symbiosis can be characterized either agronomically by increased growth and yield or ecologically by improved plant fitness (i.e., reproductive ability). In either case, the benefit accrues primarily because mycorrhizal fungi form a critical linkage between plant roots and the soil. Mycorrhizal fungi usually proliferate both in the roots and the soil. The soil-borne hyphae take up nutrients from the soil solution and transport them to the root. By this mechanism, Mycorrhizae increase the effective absorptive surface area of the plant. In nutrient-poor or moisture deficient soils, nutrients taken up by the Mycorrhizae can lead to improved plant growth and reproduction. As a result, mycorrhizal plants are often more competitive and better able to tolerate environmental stresses than are non-mycorrhizal plants.
There have been strong associations found between mycorrhizae and many fruit and vegetable crops. The mycorrhizae NZ colonise the root structures and produce hyphae into the soil which in turn improve the availability of elements such as Phosphorous, Zinc, and even regulated nitrogen nutrition. Kendra Baumgartner from USDA California found that over ninety-five (95%) per cent of crops not only respond positively to colonization by mycorrhizal fungi, but they may suffer in the absence of mycorrhizal.
Mycorrhizal Fungi in Crop Establishment
Roots, Shoots & Fruits have recently expanded their range to cover broadacre and vegetable applications. Rootella® F is a concentrated fine powder formulation suitable for dry, drip or spray application, it may be mixed with seeds in a planter box or applied in-furrow. Rootella G is a Granular product best suited when added to nursery media or for transplanting bare root and root ball plants. Tea-bag style ‘Grow Packs’ are easy to place in a hole before planting, ask for Rootella T.
Mycorrhizal fungi a key tool in the fight against global warming
We know trees and plants ‘breathe in’ C02 and remove it from the air. But where does it go? Biological sequestration involves the net removal of CO2 from the atmosphere by plants and microorganism storing it in the soil.
Enter Mycorrhizal fungi. Plants and trees take CO2 from the atmosphere through photosynthesis. CO2 enters the plant down into the roots and into the millions of miles of mycorrhizal fungal extensions in the ground. These organisms regulate carbon storage and are effectively conduits for carbon assimilated into the soil. The vast reach of the fungal web has the capacity to store huge amounts of carbon in the ground, enough to make a sizable impact on our ability to fight global warming. So soils teeming with healthy populations of Mycorrhizal fungi are an effective tool to help climate change.
The Yale School of Forestry and Environmental studies takes a closer look at this phenomenon and says… “The degradation of soils from unsustainable agriculture and other development has released billions of tons of carbon into the atmosphere. But new research shows how effective land restoration could play a major role in sequestering CO2 and slowing climate change. Many scientists say that regenerative agricultural practices can turn back the carbon clock, reducing atmospheric CO2 while also boosting soil productivity and increasing resilience to floods and drought.”
What is Glomalin?
The glomalin produced from mycorrhizal fungi stores carbon from the atmosphere, locking it up in the soil. When plants ( such as trees and grasses) pull in co2 from the air through photosynthesis, the healthy microbial connections enables the movement of the carbon into long term storage in the soil carbon pool.
Essentially, the healthier and microbe-rich our soils are, the more carbon can be taken out of the atmosphere and stored underground, where it came from. This will positively impact global warming. Mycorrhizal fungi really are a superhero in the growing world and are a valuable part of the environmental eco-system. Farmers and growers are not only providing food for the world but by keeping their land healthy they are also ensuring a healthy world for us all to live in.
The United States Department of Agriculture (USDA) AgResearch Division has commissioned research on this magic ingredient that shows the positive impact that farm soil quality can have on climate change. “Until its discovery in 1996 by ARS soil scientist Sara F. Wright, this soil “super glue” was mistaken for an unidentifiable constituent of soil organic matter. Rather, it permeates organic matter, binding it to silt, sand, and clay particles. Not only does glomalin contain 30 to 40 per cent carbon, but it also forms clumps of soil granules called aggregates. These add structure to soil and keep other stored soil carbon from escaping.”
Available for purchase now.
Roots, Shoots & Fruits has been supplying Mycorrhizal fungi to growers for two decades. The newest range of Mycorrhizal fungi, Rootella, contains more formulations to suit different types of applications, including a granular and a fine powder, with high concentrations of live organisms. Rootella is Biogro certified, and applicable to most crops especially at planting. It is important that you speak to your ag-retail rep or call Roots, Shoots & Fruits to identify the best formulation for your crop.