Josh Kiman, November 21 2022

The Quest To Replace Synthetic Nitrogen Fertilizers

Synthetic nitrogen fertilizers lie at the heart of our food system. As renowned energy and food production expert Vaclav Smil writes in his illuminating book How The World Really Works, “Given prevailing diets and farming practices, synthetic nitrogen feeds half of humanity–or, everything else being equal, half of the world’s population could not be sustained without synthetic nitrogenous fertilizers.” While synthetic nitrogen has driven substantial yield increases, its production, distribution, and application account for at least 2.4% of global greenhouse gas emissions. Vast nitrogen losses from fertilizer use result in oxygen-depleted oceanic dead zones, soil degradation, and nitrous oxide, which is 298 times more powerful than carbon dioxide in its warming effect. Significantly, as Smil underscores, nitrogen utilization efficiency by crops has declined to less than 50% and to below 40% in China and France.  

NOAA Source: Gulf of Mexico Dead Zone

On the heels of COVID, Russia’s invasion of Ukraine has exacerbated supply chain disruptions and compounded inflation through substantial price hikes in energy, food, and fertilizer. Russia typically exports 20% of the world’s nitrogen fertilizers, and farmers around the world are struggling to find fertilizer and pay its markedly higher price. As the global population swells to an expected 10 billion people by 2050 and as the middle class expands across the developing world, fertilizer will continue to play a dominant role in the global food system.

Innovative entrepreneurs are working on creative solutions to replace synthetic nitrogen fertilizers. Over the past couple years, I’ve come across some compelling companies tackling this challenge. These companies aim to provide farmers independently strong economic and environmental reasons to purchase their more sustainable fertilizers. 

Before highlighting some exciting fertilizer companies, it is important to provide a brief history of synthetic nitrogen fertilizers.     

The Haber-Bosch Process

Nitrogen is the most important macronutrient for plant growth. As Smil explains in Numbers Don’t Lie, traditional farmers supplied nitrogen by (i) recycling organic material (e.g., stalks, leaves, human and animal waste) and (ii) rotating grain or oil crops with legumes (e.g., cover crops like alfalfa and clovers and food crops like soybeans and lentils). Leguminous plants produce their own nitrogen through bacteria attached to their roots that “fix” nitrogen by converting it from the air’s inert nitrogen gas to ammonia. The grain or oil crops take up excess nitrogen from the legumes. The two natural mechanisms for generating nitrogen could not satisfy the mushrooming food demand of surging populations and cities. Organic waste collection, fermentation, and application were extremely labor-intensive and legumes necessitated crop rotation that prevented monocropping staple grain crops (e.g., rice or wheat).   

To meet the growing demand for staple crops, farms needed to find a new synthetic source of nitrogen. In 1909, Fritz Haber, a German chemistry professor, discovered how to turn atmospheric nitrogen into ammonia. Carl Bosch built upon Haber’s work to produce synthetic nitrogen on a massive industrial scale. The Haber-Bosch process uses hydrogen and atmospheric nitrogen to produce ammonia under extremely high pressure and temperature in the presence of a metal catalyst such as iron. 

During World War I, Haber, considered the “father of chemical warfare,” used the Haber-Bosch process to develop explosives and chemical weapons like chlorine gas for the German army. Tragically, Haber’s research also led to the creation of Zyklon B, which was used by the Nazis to murder millions of Jews, including members of Haber’s own extended family. World War II dramatically accelerated the adoption of the Haber-Bosch process as numerous plants were built to create ammonia for explosives. Following World War II, worldwide adoption of the Haber-Bosch process exploded to feed the rising global population, which grew from 2.5 billion in 1950 to 7.75 billion in 2020.  

While the Haber-Bosch process has been critical in feeding the global population, it is energy-intensive, its production is hyper-centralized, and synthetic nitrogen fertilizers have been pervasively overused with pernicious environmental ramifications. The Haber-Bosch chemical reaction consumes substantial energy as natural gas or coal is typically used as both a hydrogen feedstock and the energy source to attain the requisite pressure and temperature. With only approximately 500 Haber-Bosch plants in the world, substantial energy is needed to transport synthetic nitrogen fertilizers to final destinations. The pitfalls of fertilizer consolidation and fossil fuel dependence have been magnified as Russia’s squeeze on gas shipments has caused natural gas prices to soar and has forced several European nitrogen plants to shut down. As Europe imports more fertilizer, it will compete with developing nations, especially those in Africa, which are reeling from droughts, floods, conflict, hyper-inflation, and COVID’s aftermath.

Unfortunately, farmers often apply more fertilizer than recommended as a buffer against potentially poor growing conditions. When persistent application of synthetic fertilizer impairs soil health, water infiltration, and crop productivity, farmers increase fertilization in a vicious cycle further degrading the environment. There are effectively no caps on synthetic nitrogen fertilizer use, and the negative externalities associated with its overutilization are not reflected in its cost. Proper nutrient management to reduce fertilizer overuse requires education, assistance, incentives, disincentives, taxes, and regulation. As I remain skeptical of meaningful progress on such drivers, I am drawn to entrepreneurs developing lower carbon fertilizer alternatives that can also decentralize fertilizer production. Here are a few intriguing companies that have captured my attention.

Pivot Bio - Replacing Chemistry with Biology

With zero waste and a nearly zero footprint, Pivot Bio uses genome sequencing to enhance microbes’ ability to fix nitrogen for crops and thus paves a pathway to higher farm profitability and sustainability. CEO Karsten Temme underscores that half of synthetic nitrogen fertilizer, which already emits substantial amounts of carbon dioxide through its production and distribution, is not consumed by crops, thereby leading to tremendous runoff and nitrous oxide emissions. Pivot Bio taps into biology to enable farmers to curb synthetic nitrogen fertilizer dependence. 

As explained in The Corn That Grows Itself, soil bacteria evolved over millions of years to naturally fertilize plants by fixing atmospheric nitrogen that plants could absorb through their roots. Microbes benefit by growing in a more protected environment and obtaining carbon compounds generated by plants through photosynthesis. However, rampant application of synthetic nitrogen fertilizers over the past century disrupted this symbiotic relationship. Farmers liberally applied chemical fertilizers to boost yields and microbes stopped fixing nitrogen in nitrogen-saturated soil. “Because fixing nitrogen requires an intense amount of energy, microbes shuffling about in soil soaked with chemical fertilizer stopped expending the energy to carry out the process. Those microbes, in a sense, turned off.”   

Through genomic sequencing and extensive soil testing, Pivot Bio’s research team found a microbe suitable for corn and then edited its genes to fix nitrogen once again. Pivot Bio is effectively “breaking a negative feedback loop in the genome” by removing a signal in the microbial DNA that blocks it from fixing nitrogen when in fertilized soil. The microbes can thus continuously produce nitrogen absorbed directly by crop roots even in heavily fertilized soil. Pivot Bio’s products apply to corn and small grain crops (e.g., oats, barley, and spring wheat).  

The beauty of Pivot Bio’s products is to provide crop nutrition while avoiding emissions and nitrogen losses. Pivot Bio’s microbes are produced using fermentation with hardly any emissions. Furthermore, Pivot Bio’s microbes remain in the ground after rainstorms and thus protect yields and allow farmers to reduce synthetic nitrogen fertilizer application. By contrast, synthetic nitrogen washes off the field during heavy rainstorms and farmers compensate by applying additional fertilizer. Pivot Bio’s farm trials demonstrate significantly higher corn yields as “corn growers finally have a source of nitrogen that is 100% available to the corn plant.” As Pivot Bio continues to drive greater productivity, profitability, and sustainability, it will hopefully guide its customers entirely away from synthetic nitrogen. 

Nitricity - “Lightning in a Bottle”

Nitricity uses air, water, and renewable electricity to create fixed nitrogen on farms. As CEO Nico Pinkowski stresses, the fertilizer industry is one of the most centralized industries with just a few hundred Haber-Bosch factories, each of which requires tremendous capital and energy to build and operate. The hyper-consolidated nature of fertilizer production can lead to dire food insecurity, as evidenced by Russia’s war against Ukraine. Nico and his team of Stanford PhDs and postdocs set out to decentralize the fertilizer industry and quash the need for fossil fuels.

Dinitrogen, which makes up 78% of the Earth’s atmosphere, contains an incredibly strong chemical bond that requires massive energy to split. Harnessing the power of lightning, Nitricity takes solar-powered electricity contained in its reactors to break atmospheric nitrogen’s bond to produce a clean nitrogen fertilizer. As Nico explains, Nitricity’s reactor can quite literally be thought of as “lightning in a bottle.” Nitricity hopes to serve as the key bridge between renewable energy and fertilizer production. 

Nitricity’s distributed approach allows farms to produce their own fertilizer on-site using renewable energy, thus eliminating transportation emissions and costs associated with synthetic nitrogen fertilizer production and distribution. Nitricity further mitigates fertilizer overuse through an irrigation system that facilitates more precise fertilizer application. Nitricity is working very closely with farmers to identify their pain points and add key ingredients to Nitricity’s fertilizers to meet farmers’ pH and other needs so they can drop synthetic nitrogen.  

Kula Bio - Supercharging Microbes’ Nitrogen-Fixing Capacity

Kula Bio creates a biofertilizer designed to replace synthetic nitrogen fertilizers by supercharging microbes to fix nitrogen for weeks rather than hours. Co-Founder & CEO Bill Brady has had an incredibly impressive career at the intersection of technology and industry, spending 23 years at Cabot Corporation, a leading carbon black company, and co-founding Monolith Materials, the world’s largest producer of clean hydrogen. Brady has now set out to steer farmers away from chemical nitrogen, and its deleterious environmental footprint, to a sustainable biological solution. For farmers using organic fertilizers, Kula Bio is a cheaper, safer, and more effective solution that also sequesters carbon.

In his My Climate Journey podcast, Brady explains that most nitrogen-fixing microbes live for mere hours because they have to compete with other microbes for energy and food or they have to borrow energy from plants. In solar-powered proprietary bioreactors, Kula Bio injects microbes with their own independent source of energy so that when they get into the soil they can fix nitrogen for at least two weeks. During the first phase of the reaction, the microbes exponentially multiply in the presence of water and nutrients. After the nutrition mix is cut off, the water is split into hydrogen and oxygen, and then air is pumped in. The microbes begin aggressively consuming hydrogen and carbon dioxide from the air and store such energy in a bioplastic within their cell structure. When these supercharged microbes are sprayed on the soil, they draw on such stored energy to steadily fix nitrogen far longer than otherwise possible. When the microbes use up their unique energy source, they die and become an additional carbon source sequestered in the soil. 

Kula Bio maintains that its biofertilizer is far more productive and cost-effective than synthetic nitrogen fertilizers, and that it circumvents the runoff dilemma posed by synthetic nitrogen. Moreover, Brady explains that Kula Bio presents an extremely strong value proposition for organic farmers, who typically apply organic fertilizer nine to twelve months before nitrogen is available to the plants. Additionally, organic fertilizers are quite expensive and often contain pathogens. Kula Bio solves these myriad challenges through a much more sustainable and optimal mechanism that saves farmers money and time.

While Kula Bio is focusing on nitrogen, it can apply the same innovation to microbes that produce phosphorus and other key elements. Kula Bio believes its technology can ultimately create alternatives to harmful pesticides, fungicides, and herbicides. Kula Bio is currently scaling up its bioreactors to an industrial size and envisions regional sites that would each support a hundred farms. Brady stresses that Kula Bio’s technology enables decentralized nitrogen production with better economics as the energy sources will be closer to the farms. Moreover, whereas Haber-Bosch plants often cost billions of dollars, Kula Bio’s bioreactors are much less capital-intensive.

UpCycle & Co. - Turning Methane-Producing Waste Into Biofertilizer 

I recently came across Upcycle & Co., a fascinating company that converts human waste, spent beer grains, and algae into a fertilizer that regenerates the soil. I heard Founder Jared Criscuolo present at an agtech conference, and was blown away by his origin story, thoughtfulness, and deep knowledge. I reached out to Jared and he graciously shared his journey.

After moving to San Diego shortly after college, Jared became quite sick after surfing following a rainstorm. Upon learning more about runoff and water pollution in Southern California, Jared joined The Surfrider Foundation and became an environmental activist. Though his day job was in finance, he spent his free time at public hearings learning as much as possible about wastewater management and runoff. Jared founded a nonprofit to track runoff and wastewater in rivers and founded a consulting firm focused on environmental outreach and ameliorating water pollution. Through advising wastewater agencies, Jared learned about resource recovery and began pondering how to convert waste streams into valuable products. Drawing upon his understanding of wastewater treatment and the fact that farmers have been using biosludge for thousands of years, Jared began brainstorming how to create a zero emission natural fertilizer that was entirely locally sourced, manufactured (using 100% renewable energy), and sold. 

In 2015, Jared set out to create an upcycled waste brand that taps into key local themes. Jared recognized that San Diego was a farm to table pioneer and America’s craft beer capital. In addition, most people in San Diego, like Jared, are drawn to the ocean. Through his prior work and relationships, Jared was exposed to the value of algae (as a biofuel), human waste, and spent beer grains. In his backyard, Jared began experimenting with different waste blends by mounting a coffee roaster to his grill and grinding and drying different biosolids, algae, and spent beer grains he received from Ballast Point Brewing Company’s founder. Jared’s friend in Nebraska found great success when using the biofertilizer in his backyard, and Jared began raising money for Upcycle & Co. With an initial focus on landscaping, Jared signed up local nurseries and spearheaded a pilot project with Target. 

To enhance his biofertilizer, Jared has been working with a talented agronomist at Fresno State University to identify and activate microbes to improve soil and plant health. To address the higher salt content in soil by the San Diego Bay, Upcycle’s biofertilizer catalyzes microbes to drastically reduce soil salt levels and break down heavy metals. While nitrogen fixing is essential, Upcycle’s product is equally committed to enhancing stress tolerance, disease resistance, soil organic matter, plant immunity, water retention, and fertilizer efficiency so that farmers can use less fertilizer over time. When it comes to biosolids, Jared is working with wastewater agencies to properly treat human waste by eliminating all pathogens and viruses. Rather than shipping a waste product potentially hundreds or thousands of miles away, Jared can use locally sourced waste to create a low-cost and sustainably sourced fertilizer.   

While Upcycle has been focusing on landscaping, it is also running agricultural pilot projects and hoping to expand its farm reach. Jared’s laser-focus on local supply chains, circular economy principles, microbial performance, and soil and plant health is truly inspiring.


Smil points out that synthetic nitrogen use might be peaking in the developed world, but notes that the swelling developing world, including sub-Saharan Africa, will increasingly rely on synthetic nitrogen to diminish dependence on food imports. COVID, Russia’s war against Ukraine, and the disastrous environmental consequences associated with nitrogen losses have highlighted the urgent need for lower emission alternatives to synthetic nitrogen fertilizers. While synthetic nitrogen’s primacy will undoubtedly continue in the short-term, the innovative companies outlined above and investments in similar endeavors will hopefully drive a meaningful shift away from synthetic nitrogen in both the developed and developing world over the coming decades. 

Written by

Josh Kiman

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