Carbon, Climate, Crops, Soil and the Mycorrhizal Connection Workshop

By Tom Parker

Since the inception of the computing era, a simple acronym evolved to become an icon of visual acuity and perception: WYSIWYG. The concept works for tangible objects as well as for digital data, but not so much for agricultural purposes. What-you-see-is-what-you-get might be fine for digital publishing or Web site creation, but in farming the exact opposite applies—what you can’t see is what you get.

That’s because the most critical processes involved in seed germination and plant health lie beneath the surface of the soil, and even then most can only be viewed on the microbial level through powerful microscopes. This hidden world—more a universe only now divulging its secrets, scientists say—is literally the root of all agriculture. But then, the term “root” might need to be redefined as well.

According to Larry Simpson, director of training and education for Mycorrhizal Applications, Inc., in Grants Pass, Ore., roots don’t do what people think they do.

“Getting nutrients and water from the soil is actually not a primary function of the root,” he said. “The root’s main function is to host mycorrhizal fungi, and the fungi’s task is to get nutrients and moisture from the soil. It’s a symbiotic relationship that’s relatively little known. Only in the past 50 years has it started to be understood, and the vast majority of that knowledge has come to light in the last 10 to 20 years.”

While the fungi is naturally-occurring, modern agricultural procedures such as extended fallow rotations, coupled with advanced tillage equipment and huge amounts of acreage under cultivation, have disrupted its vast interconnected web, Simpson said.

“Think of a huge dense spiderweb radiating out from the actual root of the plant,” he said. “The mycorrhizal filaments extend out a couple of feet from the host plant, so many in the growing season that there might be nine miles of filaments in a single teaspoon of native prairie soil. And they’re all interconnected, whether corn or wheat or soybean. Most of that population has been lost. We’re basically planting in soil that’s lost a critical component in how plants operate and perform. It’s a downward spiral.”

Mycorrhizal fungi (literally, “fungus roots”), have co-evolved with plants and soils for more than 460 million years. They proliferate on the roots of plants in undisturbed natural habitats, spreading into the surrounding soil as a sprawling mass of microscopic hair-like threads. Host plants use their leaves to synthesize carbon for the fungi while the fungi returns the favor by supplying nutrients and water from the soil.

“The plant shares a small amount of sugar that keeps the fungus alive,” Simpson said. “Mycorrhizal fungi cannot feed themselves but require a living root to survive. If the plant dies, the fungus dies.”

Adding mycorrhizal fungus to the soil when planting seeds has several key benefits for farmers. In moist conditions the fungi acts as a primary immune system against fungal root disease caused by soil pathogens attacking the roots. In dry conditions the fungi allows host plants to not only tap into water sources more efficiently but even to store water for dry times, he said. The fungi promotes beneficial organisms that increase organic matter in the soil, thereby improving soil health, and they also help prevent potential effects from climate change through carbon sequestration.

“Farmers are always looking for better yield at less cost, and that’s what the fungi does,” Simpson said. “It increases the efficiency of the root system, enables individual plants to access more resources in the soil, improves growth in the host plant, requires less water and less fertilizer, further reducing costs. These are straightforward benefits no matter what kind of soil you have.”

Considering that these microbial interactions take place beneath the soil unseen by the farmer, it might be easy to dismiss this as nothing more than academic or commercial postulation. After all, mycorrhizal filaments are microscopic, about 1/25th the diameter of a human hair, so it’s not as if they can be seen in action. Seeing is believing, however, so participants will be treated to a walk through a freshly-dug soil pit where entire root systems can be viewed in their natural environment. The field tour will be conducted by Wes Jackson, president of the Land Institute, a nonprofit research and education organization whose goals include developing an agricultural system with the ecological stability of the prairie and a grain yield comparable to that of annual crops.

Simpson suggests that farmers who are interested but not totally comfortable in adding mycorrhizal fungi to crops start by controlled planting in contiguous sections. “When treated and untreated crops are planted side by side, they will definitely see a difference,” he said. “Our approach is to ask the farmer to try a reasonable number of acres and plant it next to a crop treated without the mycorrhizal fungi and see for themselves. It slows down the overall process but gives them confidence when they see it happening.”

Though still in its formative years, research into mycorrhizal fungi continues to unlock secrets of the interconnections between plants, soil and microorganisms. Farmers wishing to educate themselves on cutting-edge techniques based on solid science would benefit from the one-day workshop, Simpson said.

“Certainly their fathers and their grandfathers and beyond benefitted from the fungus, because in their day the soil had a natural abundance,” he said. “It was part and parcel of the ways things worked.”

Amazing Grazing 3 Partner Logos
2016-11-04T21:46:22+00:00