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Soil Focus

Elaine Ingham Reflects on the Legacy of the Soil Food Web

By Jill Henderson

Editors note: This is an article printed in the August 2021 Issue of the Acres U.S.A. magazine.

Elaine Ingham

Just a few decades ago, the prevailing consensus among scientists and agronomists was that soil was little more than a medium in which crops grew. The belief was that if we were to feed the world, the soil needed deep and regular tillage and crops required repeated applications of chemical fertilizers and pesticides. This narrow view of agriculture was the driving force behind the Green Revolution, which began in Mexico in the 1940s. Among the visionaries that would reverse the course of this new “technological farming model,” and the damage that followed, was a young microbiology student named Elaine Ingham.

Dirt vs. Soil

The starting point of Ingham’s extraordinary 43-year career in ecological agriculture began at Texas A&M, where her master’s research focused on microorganisms in aquatic systems. In 1978, Ingham switched her focus to soil after she and her husband were both offered research assistantships at Colorado State University. “That’s where I started learning about what soil actually is,” said Ingham. “And it took a while because people had such a varied understanding of what soil really was.”

At first she was confused by the various definitions of soil, so she turned to the work of the famous pedologist Hans Jenny, who had spent a lifetime studying soils in their natural environments. Jenny believed that soil formation included many environmental factors as well as “potential biota,” which was more than enough to entice Ingham to continue studying the function of microscopic organisms in the soil.

Ingham’s major professor, Dr. Donald Klein, suggested that she focus her Ph.D. study plan on fungal biomass in soil. He told her to talk to every professor at the university that worked on soil and ask them what they thought about her proposed research project, which might just prove that everyone in the field was completely wrong about soil and the role that microorganisms played in building and sustaining it.

When Ingham talked to the professors as instructed, she did not get the encouragement she had hoped for. “I have to note that there were no women at all in any of the agricultural or soils departments then. And to a man, every single one of them said, ‘You don’t want to do that research project because those organisms in soil don’t do anything. They’re not important – they’re just there. So don’t do your research. When you finish up your PhD you’ve got to be able to get a job. And if you graduate with that degree nobody’s going to hire you.’”

The Soil Food Web Connection

Despite the warnings, Ingham knew that she and her colleagues at CSU were on the cutting edge of discovery and those in her inner circle were very supportive of her work. “We knew those organisms had to be there for a reason,” she said. “There were different professors in different departments all working on the same question. So we started documenting what role they had in nutrient cycling and asking if they were a benefit to plants.”

One of Ingham’s colleagues was her husband, Ross, who was in the zoology department studying soil nematodes. She jumped into his study, working on the bacteria, fungi and some of the protozoa, while he focused on the nematodes and microarthropods. Ingham said they sterilized soil so that no organisms survived and planted wheat seeds in it. None of the seeds germinated. Then they added bacteria and fungi to the soil and the seed germinated but soon died. “If you put in bacteria plus a bacterial predator, or if you put in a fungi plus a fungal predator, they would grow. But if you added bacteria and fungi and a bacterial predator and a fungal predator, that’s when the plants grew the best,” Ingham explained. “So clearly, biology was critical.”

“The more diversity we added to the soil, the nitrogen content in the leaves of the grass went way beyond what we were seeing in the short-grass prairie outside. And the difference was that we had way more diversity and way more individuals of every species present in the laboratory because we’d been adding them from organisms from every single kind of plant we could get our hands on. We were putting all that into the mix to inoculate these magnesium microcosms with the proper sets of biology.”

Yet, they didn’t quite understand why the natural prairie outside didn’t have the diversity they thought it should. It suddenly dawned on them that the prairie they were using for comparison had been tilled extensively from the end of the 1800s right up to the advent of the Dust Bowl in the late 1920s.

In the lead-up to that disastrous event, farmers were tilling and planting seeds that wouldn’t grow. The tillage brought up weed seeds that would need to be tilled down again to save the scant crops that managed to break the surface. When nothing green was left, the lifeless dirt blew away in massive clouds of dust. The microcosm of the prairie soils had been so thoroughly destroyed by excessive tillage, chemicals and compaction that nutrient cycling could no longer happen.

Even after the dust bowl was over, the myriad microorganisms that had once been in the soil had been driven to extinction within the region and therefore could not be replenished naturally.

Ingham’s research proved without a doubt that microorganisms not only played a key role in the formation of soil but in the health of the plants that grew in it. “The soil chemists talked about sand, silt and clay – and of course, that’s just the textural part. If that’s all you have then all you have is dirt,” she said. “If you get the organisms and the food to feed those organisms, which is organic matter, then you can start talking about soil.”

The Work Continues

Elaine Ingham encourages growers to use microscopes to identify beneficial microbes.

After graduating in 1981 with a Ph.D. in microbiology with an emphasis in soils, Ingham was offered a post-doctoral fellowship in zoology from the Natural Resource Ecology Lab at Colorado State University. In 1985, she was awarded a research associate fellowship at the University of Georgia, and from there she became a faculty member in forest science and botany and plant pathology at Oregon State University, where she taught and lectured throughout the country on the soil food web she was researching.

During this time, Ingham founded her first company, Soil Microbial Biomass Service, which analyzed soils for researchers and commercial clientele. By 1996, this company had morphed into Soil Foodweb, Inc. through which Ingham developed new methods for assessing organisms in soils and on foliage and how their biology was affected by various management practices, such as the use of herbicides and pesticides that destroyed beneficial microorganisms in the soil.

In 2000, Ingham opened a new lab at Southern Cross University in Lismore, Australia, and by 2011 she become the chief scientist for the Rodale Institute. In 2015, Ingham took on the role of managing scientist at the Environment Celebration Institute in California, which was a non-profit research facility focused on scientific experiments assessing the impact of soil biology on plant production.

Throughout the years, Ingham has collaborated with organizations, industries and individuals like Jim Thompson of Huma-Gro, Ken Warner of Frontier Industries, Ron Stewart of Colombia Gorge Organics and the Edmonds Institute, among many, many others. She was driven to fine-tune ways to establish, identify and feed beneficial biology in the soil. Her work “improving the understanding of how to properly manage thermally produced compost to guarantee disease-suppressive, soil-building and nutrient-retaining composts and compost teas” is well known, as is her advocacy for “ecological testing for all geneticall engineered organisms before they are released into the environment.”

For a woman who was told she could not possibly get a job in microbiology after writing a research paper focused on the effect microorganisms had on soil, Ingham had proved them all wrong.

For the last 43 years, Dr. Elaine has been at the forefront of cuttingedge research. Her revolutionary work has resulted in hundreds of scientific papers published in peerreviewed journals, numerous magazine and newspaper articles, books, interviews, workshops and worldwide speaking engagements. Her entire life’s work has been to motivate and empower farmers, ranchers, gardeners and land managers around the world to regenerate their soils by using simple, inexpensive and quickacting methods to rebuild dirt into healthy, living soil.

Ingham’s company has recently been rebranded as Dr. Elaine’s Soil Foodweb School (soilfoodweb.com). The website greets visitors with a fresh, updated experience and offers a wide array of online courses that cover everything from the fundamentals of the soil food web to making “bio-complete” compost, extract and teas. The course on microscopy helps growers learn to identify microorganisms and interpret the data that make the soil food web come to life. And for those folks who want to take it to the next level, SFS offers advanced courses for certified lab technicians and certified foodweb consultants. To give their students plenty of time, each course is available for three years and includes personal consultations with staff as needed.

Manure and Nutrient Cycling

Finished compost on a fork.

Ingham insists that anyone, from windowsill micro-gardeners to ranchers managing hundreds of thousands of acres, can easily reclaim their soil by avoiding tillage as much as possible, keeping roots in the ground year-round, encouraging aerobic conditions and pumping up the nutrient cycling in the soil food web by introducing beneficial microorganisms to the mix.

“Exactly what do we mean by nutrient cycling?” Ingham asks. “How does your plant obtain the soluble inorganic form of nutrient that it requires without the bacteria and fungi getting their mitts on it first?”

“Even now soil scientists at universities still say that simple diffusion brings nutrients to the root system and the plant takes them up,” she said. “But, excuse me, but what is right around your root system? Every gram, every quarter-teaspoon of that soil around the root system has … a million-billion individual bacteria lying in wait for any soluble inorganic nutrient to come by. There is no way that diffusing nutrients towards the root system is going to make it into the root because the bacteria or the several miles worth of fungi around the root system are protecting your roots against diseases and pests and all kinds of nasty organisms like rootfeeding nematodes and microarthropods. It’s a castle wall.”

“You have got to have that protective layer or somebody is going to come along and attack your root system. So how does your plant ever get any nutrients? Well, that’s what the predators of the bacteria and fungi are for. They eat the bacteria and fungi and right there, right next to the root system and that membrane, the nutrients are being released from the predators. And because the concentration of those nutrients is so much higher in the bacteria and fungi that their predators have to poop it out. And that poop is just the proper form that plants need,” she said. “It’s just so elegant.”

“In terrestrial systems, we need to maintain beneficial aerobic organisms, which means structure has to be built in your soil by aerobic bacteria producing lots of glues that bind and hold the sand, silt, clays, organic matter and other organisms that will be caught in the glue to make microaggregates. You can’t see those microaggregates with your eyeballs; you’ve got to look at your soil with a microscope that lets you see at least 100 times normal in order to be able to see them in the soil,” Ingham explains. “Well, now you’ve got to do the next step in building your soil — you’ve got to have fungal hyphae that come in and they bind just like a string around a bunch of Christmas packages where it’s all pulled together in a macroaggregate.”

“The way to manage things is to maintain the aerobic conditions, which means you’ve got to have the aerobic bacteria, fungi and protozoa and the good-guy nematodes, bacterial and fungal feeders and predatory nematodes that will attack and deal with those root-feeding nematodes so that the beneficial species will be maintained. We just have to realize that and make sure that we are allowing these microorganisms to grow in the soil so they build the structure so you have the oxygen your plants and the good guys require, and you have water infiltration into your soil that moves down through the various levels and can be captured and held in the pores.”

Solutions to Big Problems

Not since the days of the Green Revolution and the Dust Bowl has the world experienced the types of ecological threats we face today. Our current reality includes climate change, massive erosion and loss of topsoil, desertification and dwindling fresh water and food resources, as well as skyrocketing plant, animal and human diseases. But it is only after a deep dive into the world through the eyes of one of the most preeminent microbiologists in the world that our future begins to look rosy again.

This is because Ingham’s solutions are not only doable but affordable and incredibly effective. One look at the results she has had reclaiming soils on six continents using her methods is enough to convince anyone that it all comes down to a thermally produced pile of biologically rich compost and compost tea. Done right, says Dr. Elaine, these two things can not only regenerate the most severely impacted soils and the crops that grow on them but can reduce the need for expensive agricultural inputs, reduce disease in livestock and create a healthier environment for all living things on earth.

Jill Henderson has been writing for Acres U.S.A. since 2013 and is a long-time contributing author for Llewellyn’s Herbal Almanac. Her books include The Healing Power of Kitchen Herbs and The Garden Seed Saving Guide. In her spare time, Jill blogs and shares her artwork at ShowMeOz. wordpress.com.