Biomimicry in Agriculture | A Way Forward

Part 2 | Ray Archuleta Series

Cover photo

March 12 & 13, 2024 – Bibulman-Wadandi Noongar Boodja

“We are all connected. We can heal the whole planet if we’re humble and mimic the natural system. Work with nature.”

Ray began with a reminder that that the pH test was designed to use in water (aqueous) solutions. The pH test was not intended to be used in a mineral matrix, like soil, as we currently use it. Therefore he cautioned that testing pH might not be appropriate to use with soil. Plants and microbes can modify pH. Plant roots can bring up calcium from deeper down to the surface to increase soil pH. Although very expensive, lime can still be applied to increase soil pH in extreme cases. A soil is said to be highly buffered if it can: 1) prevent extremes in chemistry (pH) in both directions; 2) modify the temperature to protect soil microbes and 3) retain water. We need organic matter in the soil, it’s what buffers the soil.

Ray reviewed the four ecosystem processes: 1) capture sunlight; 2) biodiversity; 3) water cycling and 4) nutrient cycling. “If one of these isn’t working your soil is dead. I want all four processes working on every cm2 of your ground.”

Soil cover prevents topsoil loss and keeps water in your soil

Moving onto soil cover, Ray shared a video on the rainfall simulator (search YouTube for ‘Rainfall Simulator’ to see similar videos). The machine mimics what happens with rain onto dry, loose soil from a clean-tilled field or onto a slice of intact surface soil from a long-term, no-till field. The no-till soil is protected with a mulch of cover-crop residue and it also has porous, stable sponge structure. The machine simulates 38 mm (1.5 inches) of rain from a storm. Most of the water applied to the tilled soil had run-off into a jar carrying with it a significant layer of topsoil. Very little water was harvested for future plant use. However, the no-till soil absorbed almost every drop of water applied and what little ran-off was clear and without topsoil. The bottom line: to prevent topsoil loss and keep the water in your soil, maintain soil cover at all times and build a sponge-like profile.

“Globally the problem we see is not enough water infiltrates the soil due to a dysfunctional water cycle. Our soils are designed to cope with 250 – 500 mm of rain. The average US conventional farm can only handle is 38 mm.” Consequently, during a significant rain event too much topsoil is lost due to run-off causing erosion. Infiltration is the key and we improve this with living plants and soil cover.

Biomimicry is the science of humility

Biomimicry uses trees, plants and animals to mimic what occurs in nature. For cropping and horticulture we exploit the natural architecture. Nature does not farm without animals. 1) Nature’s diverse. 2) It has living plants and roots and 3) The soil is always covered. Nature loves this architecture. Biomimicry uses different plants to emulate the prairie and the forest on our farms. We can roll cover-crops flat to provide an instant skin and prevent crust forming (capping), retain moisture, feed the microbes and suppress weeds.

Natural architecture follows four principles:

  1. Diversity. Cover with diversity of plants; integrate insects and animals – the more diverse the better
  2. Minimise disturbance. Limit chemical (e.g. pesticides, fertilisers), physical (e.g. tillage) and biological (e.g. over-grazing) disturbance
  3. Context: ecological, cultural, social and spiritual – context is everything. Where you live matters. Being different and not following cultural/social norms can be brutal in some places. Similarly, a spiritual connection with the land can be isolating. What is your why?
  4. Work in relationship and community – Nature is collaborative rather than competitive.

Nature is more collaborative than competitive

Ray shared results of a trial in North Dakota (brittle, with cold winters and hot summers) with 50 mm of rain. They planted several crops (lupin, oilseed, pasha, purple, cowpea) individually or in a mix. The monocultures did not survive. However, together the five species grew remarkably well. Similar results were shown from trials in Canada. These results refute the idea that plants compete with each other for resources. “Nature is more collaborative than she is competitive. We focus on competition. Regenerative agriculture taps into that collaboration. Let nature provide the inputs, we need to learn to collaborate with nature.”

Although not widely known or appreciated, results like these led to: The Stress Gradient Hypothesis that holds that as stress increases in an ecosystem, mutually supportive interactions (collaboration) become more significant and negative interactions such as competition become less so (see review by Mark Bertness, Ecology Letters, 2013). The problem, as Ray shared, “is the way we look at and think of the system. Plant and soil are not separate, they are one.”

Ray noted that competition is seen in nature as well. Competition builds regulation e.g., it serves to regulate population numbers. Competition is also a key aspect of evolution. Competition builds:

  1. Strength – the strongest survive
  2. Integrity – weaknesses / flaws e.g. genetic, reduce integrity and survival
  3. Improvement –adaption and improvement increase survival

To maximise collaboration Ray advised to always grow 4 plant classes in every paddock. David Tilman is the ‘biodiversity king’ and he suggests 5 – 15 species is optimal although this depends on your context. Where possible grow 5 – 6 species from at least 3 of the following 4 plant groups:

  1. Legumes
  2. Grasses
  3. Broadleaves
  4. Brassicas

One suggestion was to lock land up for a while and allow the seed bank to express itself. This allows us to see what plants used to grow in our context. Ray shared David Tilman allows exclusion zones e.g., flood zones, to express and go to seed. Then floodwaters carry and disperse the seed.

As an aside, Ray shared that while we often look at the body condition score of our livestock, we don’t usually look at the body condition score of our soil biology such as protozoa. Soil biology is one of the first things Ray looks at. When protozoa eat bacteria, they excrete nitrogen into the soil. Nematodes do the same thing. When nematodes and protozoa are missing from the system nutrient recycling will be poor.

Cover crops work well with no-till farming

No-till by itself is not sufficient and without cover crops it’s a recipe for failure. Nature doesn’t till. It relies on living creatures to do the tillage; plant roots, earthworms, arthropods, termites etc. Cover crops can produce dramatic changes within 3 years. Tall cover crops and rolling them flat can significantly increase production. “It’s the living dynamic soil, these plants and the microorganisms will turn your sands to hold more nutrients; they will open up your clays; they leak acids; they build carbon aggregates. Life does this.”

Ray shared he’s healed soils using plants and cows and now he’s catching up to using biological and other mineral supplements. Sometimes these agents are needed, however, they work together with cover crops and no-till. “Adding microbes won’t work if you still till. We need to think in systems. Never isolate the system.” He added “the worst thing we can do after harvest is to leave the soil bare without a living plant, you’re starving the soil.” He advocates using biological stimulants with seeds, not fertilisers per se, especially inoculants from the Johnson-Su compost bioreactor. This makes sense and is more efficient to have microbes right where the seed is. It stops microbes having to travel to and from an energy source while gathering and carrying nutrients to feed seeds and seedlings.

Ray does not recommend transitioning from conventional to organic, right away. It takes years. It’s not easy. He showcased Rick Clark, an organic, no-till farmer from Indiana who went from conventional to no-till for years before he moved to an organic, no till system.

Cover crops create a skin to suppress weeds and build soil organic matter

Rolling cover crops flat creates a skin that is allelopathic meaning it kills or suppresses weed growth. This is nature’s design. The skin helps keep the soil temperature cool. Microbes feed on the ‘skin’ to degrade it, creating a decomposition layer, and release CO2 into the bottom of the leaves and stomata, to improve crop yield. All healthy soils have skin. Look between blades of grass in your lawn and you will see a natural skin – the dedritusphere – where plant residues degrade. Beneath the skin is the aggregation zone or aggregatusphere where aggregates are formed. Ray noted, in more brittle environments we want more carbon in our cover crops because we don’t want it to break down too quickly. The carbon slows down its rate of degradation.

Organic matter cannot be built without living plants and water. To build soil nitrogen the soil needs carbon (from plants); and we can’t build soil carbon without nitrogen. Both are needed; we can’t achieve one without the other. Only plants can do both. Plant roots exude carbon molecules into soil and in the case of legumes they can fix nitrogen in soil as well. Furthermore, as plant matter (carbon) degrades in soil it draws nitrogen into the soil.

Building organic matter will require a big shift in our thinking especially with water – we need to use water to save water until the system reaches an equilibrium. “Please understand, your soils are very degraded and have a long way to go. Very few farms I’ve visited have impressed me. Gabe Brown’s farm in the US is one. Even Gabe says his soil has a long, long way to go.”

Ray added, “Farmers are geniuses. They are incredible engineers.” He shared the story of Lucas Griswell in the US, who grows two crops at the same time, wheat and soybean, with high yields for both. After harvest, the corn is rolled to provide the skin, suppress weeds and feed the microbes improving soil biology and productivity. Human creativity is a tool we need to use more. Ray applauds farmers, “once farmers get the concept, they’ll figure it out, they’re brilliant.”

Ray was asked how much soil disturbance is too much? He says it depends on your context and the inherent qualities of the soil: climate, temperature and what ecosystem it was before. Even a bit of disturbance like tillage can dramatically effect crop production. It also depends on whether we use cover crops that can reduce soil temperature 10 – 11°C at a depth of 2.5 cm. Today, the four best soils in the world are: 1) the mid-west USA; 2) Argentina; 3) Ukraine and 4) a part of China. Before we started farming them, these regions were all deep, prairie soils, grassland soils with buffalo. “We wiped out the buffalo, got rid of the warm-season grasses and look at what we have now…”

Biomimicry is to design the right plant for the right purpose at the right time

Biomimicry is being intentional with our design. The right cover crop mix planted in the spring prevents weed growth that would harm a fall wheat crop (US seasons) and avoids the application of herbicide. Seed is expensive, we don’t want to waste it. Be intentional.

Ray briefly mentioned carbon to nitrogen ratios. The browner a stem, trunk or branch is the higher the ratio is (more carbon). The greener it is the lower the ratio is (more nitrogen). A brown trunk typically has 80-100 molecules of carbon to one molecule of nitrogen. When it breaks down in the decomposition layer in soil the ratio drops to 12:1 as it draws in nitrogen. Globally, most soils will approach a 12:1 ratio. In soil pores we want a ratio less than 20:1. “Modern conventional agriculture struggles to achieve a 12:1 ratio. It doesn’t mimic the prairie, there’s too much bare ground” and not enough carbon from plants.

Plants feed microbes, bare ground does not. Cover crops also serve to feed the microbes between our crop plants. They provide a service to our crops and to the microbes. One reason cover crops aren’t more widely used is in the US, farmers think cover crops are used to prevent soil erosion. Ray says cover crops are biological primers, they feed the biology and enhance the life and function of soil. Consequently, Ray prefers the term service crops rather than cover crops. They service: the climate; the cow; the biology; the next crop. They service everything.

Ray showcased a remarkable video highlighting what cover crops can do in a very cold climate. For a conventionally grown wheat crop during the winter in Kansas the typically frozen ground prevents a penetrometer going into the ground. However, a summer and winter mix of soil cover crops stopped the ground from freezing and allowed a penetrometer to easily enter the soil despite the sub-zero temperatures. The cover crops keep the soil warmer but more importantly, they maintain the biology and the aggregates and pores to stop the soil from freezing. The aggregates are everything, they are the home of the biology.

Ray explained the military-industrial way of thinking where everything looks like either a hammer or as a nail. That is all they see. It’s very reductionist. A plant pathologist says “I’ve got to cure the disease.” Natural systems control their own disease. They regulate their own pathogens. This is why monocultures, that aren’t natural systems, are prone to fungal or bacterial diseases. The overuse of nitrogen-based fertilisers is like providing a pantry of goodies to feed fungi and bacteria and result in micro-toxins going way up. The plant pathologist’s reductionist solution to disease is often to ‘throw the baby out with the bathwater’ and start over. Rather than focus on how to solve the problem it’s better to focus on what caused the situation to occur in the first place.

Ray stressed by comparison “regenerative agriculture is heaven, although it’s not quite there yet. I have less disease, less pathogens if I mimic the natural system. Nature’s self-healing, self-organising, self-regulating. Just like we are when we get sick. We get pest outbreaks because there has been a climatic shift, we’re not getting (the climate) as cold anymore. Pest management in the US is like this. A farmer has a pest and calls for help. An expert comes and sprays to get rid of it. A neighbour hears about it and asks what did you spray for? So he sprays for the same thing. Before you know, it the entire county has sprayed. It’s like taking chemotherapy just in case you get cancer. Farmers don’t check if they have the problem or if they’ve reached economic threshold. If not, chill out. Unfortunately, we don’t do this.”

Integrate animals into our farm systems to mimic nature

Ray grew up near the Chihuahuan Desert in New Mexico. He shared images of how he was taught at college to make orchards with lots of bare ground around the trees because ‘bare ground won’t steal water or nutrients.’ This a competition mentality. He showed how they now grow nuts e.g., walnuts in New Mexico with plants around the trees. “Cycling went up. Organic matter went up. We created a habitat for beneficials. Disease went down. Yield stabilised. We used less water, not more, because we had less evaporation. This is mimicking nature. We’re now adding sheep to generate more income for the farmer.” He added “in the US they’ve now introduced rules in the organic industry that says farmers can’t use sheep in their system to prevent possible E. coli outbreak from sheep manure. The problem with rules like these is they ignore the dung from chipmunks or deer. Worse, they forget that E. coli is denatured by sunlight and we end up with more and more restrictions on the producer. This is why farmers don’t want to be organic, there’s too many rules and they don’t understand what the rules are about.”

Plant multispecies cover mixes and let the animals express their genetic potential. Plants and animals co-evolved together. Ray says no-till won’t work without integrating grazing animals in brittle environments. Brittleness refers to the presence of humidity at ground level across the year. Brittle environments have low humidity most of the year. In brittle environments, farming removes you from your ecological context and we need to graze animals to restore the context.

We need infrastructure to heal our land

Ray’s colleague, Alejandro Carrillo, has caused amazing results on his 12,000 hectares in New Mexico where soil surface temperatures can reach 67°C (enzymes and soil life shuts down above 40.6°C). Alejandro uses lots of paddocks, and a single hot-wire to divide the paddocks with long recovery periods between grazing once or twice a year. They designed their own water points. Allan Savory provided the inspiration. Bunching the animals tightly changes their behaviour. Their hooves break the crust. Dung and urine add nutrients and biology to the soil. This causes weeds and other grasses to grow. Importantly, when tightly bunched, the animals will eat everything, not just the tasty plants they want to eat. Selectivity is removed when we introduce competition. Ray suggested we can use epigenetics to our advantage to adapt our animals over time to graze and eat everything in our landscape. For instance, cows can adapt to eat cactus. Donkeys will eat almost anything and might be a great animal to start with in very degraded / poor landscapes. A multi-species herd comprised cows, sheep, donkeys might be ideal. Incredibly, Alejandro moves his cows 800 time per year (2-3 times every day). With each grazing cycle we continue to build the soil and health of the landscape. Ray cautioned “it takes years to restore soil with cattle. Plan for the future, 20-30 years ahead.”

Ray referred to an interesting paper: Mobile link organisms and ecosystem functioning: implications for ecosystem resilience and management by Jakob Lundberg and Fredrik Moberg. If an area of land is functioning well and we then introduce a mobile-linked species e.g., bats, bees or cattle. The mobile species will transport the biology via dung and urine into a non-functioning region nearby. Moving cattle also brings seed on their hide, under their hooves, in their dung to introduce plants species. This is biological communication between animals and soil. Alejandro’s work is highlighted in the new movie Common Ground, the sequel to Kiss The Ground. Ray says if we can heal the Chihuahuan Desert where it’s hot, brutal and dry, we can heal Australia. “Cows will save the world.”

Ray recommends books by Masanobu Fukuoka who said “I realise that rain does not come from the heavens it comes from the ground. Desert formation is not due to the absence of rain but that the rain ceases to fall because the vegetation has disappeared.” We now know scientifically that plants and trees release terpenes and with bacteria cause raindrops to form in a process known as bio-precipitation. Bacteria and biology are everywhere. Even we are comprised 90% bacteria.

It is not the scale, it’s the thought process that matters

Ray shared the story of Tom Minocek in the US who has done amazing things restoring 5-acres with 2 cows. It is not the scale that matters, it’s the mindset. Ray also suggests reading “You are not so smart” by David McRaney. It addresses social bias and logical fallacies. Regenerative agriculture, like biomimicry, starts with humility, because we’re not that smart. Ray concluded the session with a video showcasing the work of a humble Indian who walked into the desert and planted one tree every day for 37 years. All by himself he literally grew a forest, now with elephants and tigers, out of the desert. Watch the video here.