The article below is based on a podcast interview with Dr. Barry Goldman.
Imagine a world where agriculture relies on the power of microbes to grow healthier crops. What if the key to sustainable farming is not found in a laboratory but beneath our feet, hidden within the soil?
For farmers, agricultural scientists, and sustainability advocates, this concept isn’t just intriguing — it’s revolutionary. As we face growing challenges from rising input costs, herbicide and pesticide resistance, soil degradation, and climate change, the need for more sustainable and efficient farming methods is critical.
The solution lies in understanding and harnessing the full potential of microbes through innovative products like biofertilizers, biopesticides, and biostimulants. These tools can offer sustainable alternatives that not only enhance crop yields but also improve soil health and reduce environmental impact.
In this blog post, we will explore how microbes are useful in agriculture, how cutting-edge microbial technologies are being developed to address key agricultural challenges, and what the future of agricultural microbiology holds. You’ll learn about the benefits of agricultural biologicals like biofertilizers, biopesticides, and biostimulants, the challenges of implementing microbial solutions, and innovative companies leading the way toward a greener, more sustainable future in farming.
The Hidden Microbial Ecosystem Beneath Our Feet
Soil is often seen as simply a foundation for plants, but it’s home to a diverse and vital community of microorganisms. These unseen organisms play a critical role in supporting plant health and agricultural productivity. A single handful of soil can contain up to 5,000 different species of microbes, showcasing the remarkable complexity of this microbial ecosystem.
These microbes aren’t just passive residents of the soil; they actively contribute to plant growth, nutrient cycling, and disease prevention. Their interactions with plants and other organisms create a dynamic network of relationships that directly influence the health and productivity of crops. Understanding and harnessing this hidden microbial world has the potential to revolutionize agriculture by offering sustainable solutions that reduce reliance on synthetic chemistries.
This is where innovations in agricultural biologicals, such as biofertilizers, biopesticides, and biostimulants, come into play. These often microbial-based products leverage the natural abilities of soil microbes to enhance plant growth, protect against pests, and improve stress tolerance. By tapping into the power of these microorganisms, scientists and companies are developing cutting-edge solutions that not only promote healthier crops but also foster more sustainable farming practices.
In the following sections, we’ll explore how biofertilizers, biopesticides, and biostimulants are transforming agriculture and what challenges remain as we seek to optimize these microbial-based innovations.
Biofertilizers
Biofertilizers are biological products that increase nutrient availability. These products, often containing beneficial bacteria or fungi, improve soil fertility.
Nitrogen-fixing Rhizobium
One classic example is the symbiotic relationship between Rhizobium bacteria and legumes. Rhizobium is a nitrogen-fixing bacterium that forms a symbiotic relationship with legumes, growing inside root nodules. In these nodules, Rhizobium fixes nitrogen, which is essential for plant growth. This bacterium supplies nitrogen to the plant, and the plant provides sugars to the microbe.
This partnership has been leveraged by farmers for centuries to boost crop yields naturally. As Dr. Barry Goldman, founder and Chief Science Officer of Pluton Biosciences, noted in our Joyful Microbe podcast interview, “That became a model, and that’s been used for years in Brazil. And it’s because the soil in Brazil is very poor. They grow a lot of soybeans, as many soybeans in the US, about 80 million acres, and they have to supply rhizobium.”
Innovations in Nitrogen Fixation: Pivot Bio’s Approach
While Rhizobium bacteria have long been central to nitrogen fixation in legumes, new technologies are expanding nitrogen fixation to other crops.
Pivot Bio has developed a product, Pivot Bio PROVEN, that improves nitrogen fixation in corn. They have identified a nitrogen-fixing endophyte, which is a microorganism that resides within the plant. Normally, nitrogen fixation is an energy-intensive process, and when ammonia is present, the microbe turns off its nitrogen-fixing ability to conserve energy. Pivot Bio engineered the microbe to bypass this inhibition, allowing it to continuously fix nitrogen even when ammonia is present.
This innovation enables farmers to reduce their reliance on synthetic fertilizers, which, in turn, decreases the greenhouse gas emissions from the production of fertilizers via the Haber-Bosch process. As Dr. Goldman explained, “The farmer can replace some of the synthetic fertilizer that he or she is going to be applying to the field, and by replacing that synthetic fertilizer, you have two impacts….you can reduce making synthetic fertilizer and the greenhouse gasses associated with it, and you can save the farmer money.”
While it doesn’t completely replace synthetic fertilizers, the product has the potential to significantly reduce the need for synthetic fertilizers, offering both environmental and economic benefits and contributing to more sustainable farming practices.
Biopesticides
Biopesticides, derived from living organisms, offer an eco-friendly alternative to traditional synthetic pesticides. Unlike synthetic chemistries, biopesticides minimize risks to human health and the environment, making them a cornerstone of sustainable agriculture.
Bacillus thuringiensis (BT)
One of the most well-known biopesticides is Bacillus thuringiensis (BT), a bacterium used for decades to combat insect pests. BT produces proteins that are toxic to certain insects, offering a targeted approach to pest management. This precision reduces the need for broad-spectrum synthetic pesticides, which can harm beneficial insects and disrupt ecosystems.
In the late 1970s, scientists identified the genes responsible for BT’s insecticidal proteins. This discovery led to genetically engineered crops that express BT genes, allowing plants to produce their own natural insecticide. As Dr. Goldman noted, “It turned out to be much more effective to take the genes and express them in the plants.”
BT-expressing crops have transformed pest management by decreasing pesticide use and cutting costs for farmers. However, BT is just one aspect of a broader strategy. Researchers are now investigating additional microbes to address various agricultural pests effectively.
Innovative Microbial Biopesticides for Agricultural Protection
New advancements in bioprotection are expanding beyond traditional biopesticides like Bacillus thuringiensis (BT). Companies such as Indigo Agriculture and NewLeaf Symbiotics are developing microbial solutions that work in innovative ways.
Indigo Agriculture has introduced a microbe that specifically targets nematodes, a major threat to crops. When applied around the roots, the microbe resides in the soil, and when nematodes consume it, their populations are reduced.
Meanwhile, NewLeaf Symbiotics offers a different approach by utilizing microbes that enhance a plant’s natural defenses. These microbes boost the plant’s immune response, making it more resilient to insect pests.
These bioprotection methods represent a growing interest in more sustainable and biologically driven agricultural practices.
Biostimulants
Biostimulants are a diverse group of substances that, unlike fertilizers, don’t directly provide nutrients but instead stimulate plant growth and resilience. Microbes are often a key component of biostimulant mechanisms, whether they are the biostimulant themselves or are affected by it, ultimately helping plants to better acquire nutrients, produce hormones, and cope with environmental stresses.
These biostimulant microbes can reside inside (endophytes) or on the surface (epiphytes) of plants, stimulating growth and vigor. For instance, certain microbes produce auxins that promote root development, helping plants to establish a robust root system.
Arbuscular mycorrhizae fungi associate with nearly every plant species and significantly improve phosphate uptake. By integrating with plant roots, they enhance the plant’s access to essential nutrients.
A novel concept emerging in the study of plant-microbe interactions is called “rhizophagy.” This idea suggests that certain plants can attract microbes and essentially “eat” their insides. “They secrete what are called exudates, or nutrients. The microbes go toward them, and then the plant releases superoxides that bust open the bacteria, and then the plant sucks up its nutrients. So, in this case, the plant is a parasite of the microbes,” explains Dr. Goldman.
Innovative products are being developed to leverage these types of plant-microbe interactions. For instance, Sound Agriculture’s product, Source, is a small molecule that activates the microbiome near the roots to produce nitrogen and phosphorus.
This advancement and others reflect a growing understanding of microbial interactions in agriculture and their potential to support sustainable farming practices. By improving how plants interact with their environment, biostimulants enhance crop yields without the environmental downsides of synthetic chemistries.
Summary of Microbial Agricultural Biologicals
After discussing the important roles of microbial agricultural biologicals, it’s useful to have a quick reference. The table below summarizes the key features of each biological, including their definitions and examples. This overview will aid in easily understanding how these products contribute to sustainable farming practices.
| Microbial Agricultural Biologicals | Definition |
|---|---|
| Biofertilizers | Biological products that improve plant growth by enhancing nutrient availability and soil fertility. They often include bacteria or fungi that assist in processes like nitrogen fixation or phosphorus solubilization. Example: Rhizobium bacteria used with legumes for nitrogen fixation. |
| Biopesticides | Biological agents derived from microbes that control pests, weeds, or pathogens. They offer a targeted approach to pest management by using natural toxins or stimulating plant defense mechanisms. Example: Bacillus thuringiensis (BT) used for insect control. |
| Biostimulants | Substances, including bacteria and fungi, that stimulate natural plant processes, improving nutrient uptake, growth, and stress tolerance. They often promote root health and enhance plant resilience against environmental stress. Example: Microbes that produce growth-promoting hormones like auxins. |
The Challenges and Future of Microbial Agricultural Biologicals
While microbial solutions for agriculture show great promise, their application in real-world farming is not without challenges. Microbes, being living organisms, are sensitive to environmental factors such as soil conditions, temperature, and humidity, which can influence their efficacy. This unpredictability contrasts with the more consistent results farmers expect from synthetic chemistries.
As Dr. Goldman explains, the initial hopes for biologicals have faced hurdles: “I think everybody hoped you could just grow up a culture of Bacillus thuringiensis, spray it on a plant, and that would protect you. That would be a great way to do it. It just hasn’t worked out that way.” Farmers may resist adopting these new methods if they lack the reliability they’ve come to expect from synthetic solutions. However, agricultural companies developing these biologicals are working to standardize microbial formulations, ensuring that farmers can rely on them to perform consistently across a variety of conditions.
Balancing Efficiency and Sustainability
Synthetic pesticides and fertilizers are highly effective, which is why they remain widely used. However, the environmental costs are high. Microbial products offer a sustainable alternative that benefits soil health, reduces greenhouse gas emissions, and mitigates pollution. As research progresses, these products will likely become both more efficient and easier to integrate into modern agricultural practices.
Microbial Applications: A Holistic Approach
The way biologicals are applied in agriculture is crucial for their effectiveness. Farmers have various options, such as treating seeds, spraying crops, or applying microbes directly to the soil, each with its own advantages.
Combining or stacking different microbial products has the potential to further enhance plant growth and soil health. For instance, applying beneficial photosynthetic microbes to the soil surface can improve soil structure and provide nitrogen, reducing the need for synthetic fertilizers. At the same time, products like Pivot Bio PROVEN can be applied directly to the root zone to optimize nitrogen fixation. By using these complementary approaches, farmers can create a more effective and sustainable agricultural system that supports both plant nutrition and soil vitality.
Pluton Biosciences: Unlocking Microbial Diversity for Agriculture and Climate Solutions
Having explored the various innovations in biologicals from companies like Indigo Ag, Pivot Bio, NewLeaf Symbiotics, and Sound Agriculture, let’s now turn to Dr. Goldman’s company, Pluton Biosciences.
Founded with the mission of tapping into the immense microbial diversity on Earth, Pluton aims to develop innovative solutions for agriculture and climate change. While estimates suggest there may be close to a trillion species of microbes, agricultural products have traditionally relied on just a few hundred. As a taxonomist and microbiologist, Dr. Goldman saw this as an opportunity to harness the power of vastly more diverse microbial populations to transform agriculture.
Instead of isolating one microbe at a time — a process that would take centuries to explore fully — Pluton developed a method called “micro mining.” This approach examines populations of microbes in soil samples, narrowing them down to smaller, manageable groups that can be tested for beneficial properties.
Using this process, Pluton has discovered a unique microbe with the ability to produce a small molecule that kills the insect pest fall armyworm. By refining this molecule, they’ve developed a new chemistry that is not only highly effective but also safer and capable of overcoming insect resistance — a major issue with conventional chemistries.
Another one of Pluton’s key projects involves photosynthetic nitrogen-fixing microbes that can also sequester carbon. Lab tests have shown these microbes can sequester close to a ton of carbon per acre, with the potential to remove a significant portion of global CO2 emissions if applied on a large scale across farmland. As Dr. Goldman explains, “You could be improving the health of the soil by putting carbon dioxide converted into sugars back into the field, as well as fixing nitrogen and replacing synthetic fertilizer.” This approach not only mitigates climate impact but also enhances soil health by enriching it with sugars from converted CO2.
The Path Forward: Innovation in Agricultural Microbiology
Microbial agricultural biologicals, from biofertilizers to biopesticides and biostimulants, represent a transformative shift in farming practices, offering a sustainable alternative to synthetic chemistries and reducing environmental impact. These innovations not only enhance crop health and productivity but also hold the potential for improved yields, healthier soils, and a smaller environmental footprint. As research advances and microbial products become more reliable, farmers will increasingly adopt these solutions, balancing high yields with the need to preserve soil health and protect ecosystems. The future of agriculture is rooted in the unseen world of soil microbes — powerful, natural allies that hold the key to more sustainable farming practices and a healthier planet.
How Microbes Are Useful in Agriculture: Dr. Barry Goldman
