In this episode of CleanTech Talk, I sit down with Karsten Temme, PhD, geneticist, and CEO of Pivot Bio. His company, founded with his long term academic collaborator Alvin Tamsir, is based on a eureka moment. They’d been analyzing nitrogen-fixing microbes in soil, with the intent of inserting the genetic codes in plants. The microbes naturally fix nitrogen from the air in return for sugars from the plant roots, but that’s suppressed by fertilization. But changing plant genetics was hard. Then, as they walked out for coffee one day, they asked “What if we turned off the nitrogen sensors in the microbes instead?” And now they have a million acres under cultivation and $430 million in Series D funding.
Agriculture is a blessing and a curse in human and climate terms. It’s absolutely necessary to feed the world’s population. It’s been getting radically more efficient through the decades of the green revolution, with automation, fertilizers, pesticides, herbicides, and more productive strains of crops increasing yields an enormous amount.
The land actually under cultivation has barely changed since 1950. We’re feeding vastly more people with the same land area. And the amount of ammonia-nitrogen fertilizer has barely changed since 1950 either, which is a good thing, as fertilizer is very large source of greenhouse gases. But we’ve lost 21% of Green Revolution gains to climate change over the past decades as well.
Fertilizer is created with hydrogen from fossil fuels — 37% of the annual global hydrogen market — with 8-35 times the mass of CO2 as of hydrogen created. It’s distributed with diesel-engine ships, trains, and trucks. It’s spread with diesel tractors on fields globally. Much of it washes off or is in the wrong place, meaning about half of the fertilizer spread doesn’t actually help. It combines with oxygen to turn into 265–298x CO2 global warming potential nitrous oxides. And when it washes off, it disrupts the environment, changing the biology of waterways and in many places creating algal blooms and dead zones that choke the ecosystem under the waves, killing fish and marine mammals.
Agriculture’s direct contribution to climate change is from 8-17%, with the OECD using the high end of that range. Addressing agriculture’s contribution is a fundamental requirement to solving the climate problem.
But agriculture has also significantly degraded the ability of the land it covers to act as a carbon sink. This is mostly as a result of high-tillage agriculture, which turns over the soil every year prior to fertilization and seeding. There are two components to why this is a problem. The first is that this exposes all of the biomass under the ground to rapid aerobic decomposition, quickly returning temporarily sequestered CO2 back to the air. The second is that it disrupts the underground fungal root network which carries the glomalin protein necessary for long-term soil sequestration of carbon. Shifting to low-tillage agriculture is a key wedge in climate action, and comes with a lot of benefits, including substantially less erosion.
Precision agriculture plays a part here as well. That model of farming uses GPS, sensors, and computer controlled seeding, fertilizing, and other machinery to put chemicals and water exactly where they most benefit the plants. No more covering an entire field in fertilizer, pesticides, and herbicides.
And here’s where Pivot Bio’s solution comes in. It’s the biologically supercharged version of precision agriculture. Temme and his research partner mapped nitrogen-fixing microbes’ genomes, intending to insert the genetic codes for it into the plants. The microbes that do this eat sugars emitted by the roots of plants, and in return provide nitrogen. However, like all life, the microbes are lazy. They only create nitrogen when there isn’t very much there, which enables the plant to grow and provide them with the sugars they need. Evolution at work.
The insight that the Pivot Bio founders had was they they could turn off the sensors for nitrogen, leading to microbes that always made nitrogen, regardless of the amount of nitrogen fertilizer that had been spread. And so they took out the bits of the genome that did that, and bred a set of microbes that turned into permanent nitrogen factories.
Then they brew them in microbrewery-scale fermenters, package them up, and deliver them to farmers.
Now they have a million acres of US corn being grown with their product. Either a spray of microbes goes down with the seed in a precision agriculture model, or the seeds are coated with the microbes before seeding, both of which are standard practice for farmers. The microbes bind to the roots of the plants as they grown, and provide nitrogen exactly where it is needed.
Every bushel of corn or grain requires about a pound of nitrogen. For an acre, Pivot Bio’s solution replaces about 40 pounds of fertilizer. That’s about 20-25% of the required nitrogen. Their target is 100% replacement of fertilizer by 2030, which is an ambitious goal.
40 million pounds of fertilizer were displaced by their product in the past year alone, meaning hundreds of millions of pounds of CO2e avoided as well. As this type of solution spreads across the world, agriculture’s greenhouse gas emissions will drop a lot.
There are more benefits as well. Fertilizer is added multiple times through the year. Most is added at year-end when the field is tilled, ready for planting in the spring. And then 3-4 more runs of fertilization over the growing season. But the Pivot Bio solution displaces 1-3 of those passes over the soil with heavy equipment, improving soil life and the biome under the surface, reducing farmer labor, reducing wear and tear on agricultural machinery, and reducing diesel engine CO2 emissions.
There’s a reason why Pivot Bio has gone through several successful funding rounds, most recently a $430 million Series D round. Its product is not only good for the climate and good for crop yields, it makes farmers’ lives easier.