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Agriculture

Published on September 17th, 2020 | by Carolyn Fortuna

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You Need To Know About Nitrogen Pollution — A CleanTechnica Exclusive

September 17th, 2020 by  


Today, agricultural growers apply nitrogen in the form of synthetic nitrogen fertilizer. Roughly half of the synthetic nitrogen fertilizer goes unused by the crop and is lost to waterways, where it feeds harmful algae instead of crops and results in red tides and hypoxic dead zones. Human nitrogen additions to the soil, in the form of fertilizers, reinforce the greenhouse effect: around 60% of nitrous oxide is emitted from fertilized fields, manures, and other agricultural sources. Nitrogen pollution is often a forgotten element of climate change.

Nitrous oxide (NO2) depletes the ozone layer and is 300 times more potent than CO2. The biggest source of NO2 is agriculture, a method more than 100 years old. It really hasn’t changed much and, over time, has become less effective in providing crops with nutrition.

nitrogen pollution

Image courtesy of Pivot Bio

A person in the US has a nitrogen footprint of about 41 kilograms a year, compared to 24 kilograms for an average person in the Netherlands, says Allison Leach of the University of New Hampshire. Addressing the fertilizer failings of modern farming must be part of climate crisis solutions.

We at CleanTechnica were able to connect with Karsten Temme, CEO of agtech startup Pivot Bio, to discuss the issue and learn more about why microbes can be the key to curbing nitrogen pollution. Karsten Temme is co-founder and CEO of Pivot Bio. Temme holds a PhD in Bioengineering from University of California-Berkeley and received his bachelor’s and master’s degrees in Biomedical Engineering from the University of Iowa. While earning his PhD, his graduate research focused on enhancing the nitrogen-fixing potential of soil-borne microbes.

Karsten Temme photo courtesy of Pivot Bio

How is nitrogen pollution more hazardous to the environment today than ever?

As has been well-documented, there is a shortfall between the amount of food we produce today and the amount needed to feed our rapidly growing population. In the next 30 years, we will need to produce 56% more food while reducing greenhouse gas (GHG) emissions by 73%. It’s clear that dramatic solutions are needed.

140M metric tons of synthetic nitrogen fertilizer is manufactured annually to sustain the production of cereal crops, and this number is expected to continue growing by at least 1.5% per year. Between the nitrogen lost to the environment and the environmental footprint of the manufacturing process to create it, synthetic nitrogen fertilizer alone is responsible for 2.5% of global GHG emissions. Over time, the climate change impact could be devastating – unless we think differently about how nitrogen is delivered to crops.

What has changed in the chemical/ industrial world which makes nitrogen so much more prevalent than in the past?

What’s critical to understand in this conversation is what hasn’t changed. For nearly a century, agriculture has relied on the same industrial manufacturing process to create traditional fertilizers and apply the nitrogen to crops. The Haber-Bosch process used to make 90% of synthetic nitrogen fertilizer emits three tons of carbon dioxide for every ton of ammonia. At the scale and volume of synthetic nitrogen fertilizer production today, this energy-intensive chemical synthesis contributes to 1.5% of annual GHG emissions.

In combination with mechanization and improved plant varieties, synthetic nitrogen fertilizer has become a staple of modern agriculture. Since its introduction 100 years ago, it is responsible for fully half of our improved productivity and today farmers in the US use 40 times the nitrogen fertilizer their grandparents did. However, because half of that fertilizer is lost to the environment, they’re spending nearly 6 billion dollars on nutrients that never reach the plants.

Nitrogen loss impacts farmer productivity and financial health, but it also results in global pollution from N2O volatilization and nitrate leaching. Concerns around N2O pollution are slowly being recognized by international agencies like the United Nations Environment Programme (UNEP). Academics have tried to find a way to get cereal crops to fix their own nitrogen for decades, knowing that if they could find a solution, it would have a tremendous environmental impact.

How does nitrogen pollution fit into the larger picture of the climate crisis?

When synthetic fertilizer is applied to fields, about half of what is applied is used by the crop. The other half leaches into waterways in the form of nitrates, affecting water quality and contributing to the 500 dead zones in the oceans. It also volatilizes into the air as nitrous oxide, a GHG that lasts 100 years, destroys ozone, and is about 300 times more powerful than CO2. Volatile weather results in the nitrogen loss that drives these reactions. That same nitrogen loss also threatens yields, so growers are inclined to use excess synthetic fertilizers to buffer against losses.

The excess of synthetic nitrogen fertilizer means productive crops – but it also impacts the natural relationship between crops and soil microbes, causing microbes to switch off their natural abilities to provide nitrogen to the crops. They sense high levels of synthetic nitrogen fertilizer and consequently switch off their biochemical pathways to conserve energy and resources.

Nitrogen pollution is a difficult problem to solve. Even the most carefully applied synthetic nitrogen fertilizer is susceptible to weather events, and once nitrogen is lost to water through leaching or lost to the atmosphere through volatilization, it can cycle repeatedly through different environments and jurisdictions. To confuse matters further, the nutrient is essential to our continued agricultural productivity. Any solution has to preserve the nitrogen that makes it into the crop while eliminating the nitrogen that would be lost to the environment.

nitrogen pollution

Image provided by Pivot Bio

What alternatives exist to synthetic fertilizers, and at what cost could they be implemented?

The best solution to reducing excess nitrogen while maintaining productivity is nitrogen produced on-demand by microbes living in symbiosis with cereal crops. My co-founder Alvin Tamsir and I founded our company, Pivot Bio, out of an ambition to replace synthetic nitrogen fertilizer with something more sustainable and safer for farmers to use. Together, we developed a new crop nutrition solution called PROVEN™, the first nitrogen-fixing microbe for corn, and built a company laser focused on workable, sustainable solutions for farmers that improve the health of the planet through scientific innovation.

Nitrogen-fixing microbes for cereal crops are a new and exciting tool in a very limited toolbox. Now, farmers are able to pay only for the nitrogen they will use, continuing their tradition of land stewardship and conservation while protecting their productivity and ensuring their operation is profitable. The daily doses of nitrogen produced by nitrogen-fixing microbes support efforts to grow more food with less nitrogen loss, resulting in a lighter environmental footprint, helping make our water cleaner and reducing GHGs generated by agriculture.

These microbial solutions are essential to the future of our planet, and Pivot Bio expects to displace a gigaton of CO2 emissions in the next 10 years. This is comparable to taking over 200 million cars off the road or planting 16 billion trees and letting them grow for 10 years.

What cultural and systemic changes would be necessary to see these alternatives become common agricultural practice?

For growers, adopting new technologies boils down to one question: Does it work better than what I’m using today? Because the nitrogen is produced continuously by the microbes, the corn crop gets nitrogen when it needs it the most. Our challenge is in ensuring farmers know about this option, so they can affordably incorporate it into their planting and nutrient management plans. We are sensitive to the tight operating margins and risk-aversion of the industry. So we’re doing everything we can to ensure farmers have access to Pivot Bio PROVEN™, from connecting a nationwide network of trusted independent retailers to building the machinery growers need to apply the product.

Precision nutrient delivery by microbes is one of the most revolutionary inventions in modern agriculture. But Pivot Bio is more than just a single product. As a long-term partner to the farmer, we’re developing tools to help farmers feed our growing population and keep farms sustainable and profitable for the long term.

What do our readers need to know about microbes? How can they become key to sustainable agriculture practices?

Healthy soil is full of microbes breaking down organic matter and building the complex matrix of minerals and organic compounds that plants love to grow in. Just like your own microbiome, the soil microbiome has many functions. One of the most important is supporting plant nutrition.

Microbial solutions, derived from naturally occurring microbes like bacteria and fungi, can replace or complement traditional fertilizers. What’s unique about Pivot Bio’s microbes is that they continue to fix nitrogen in agricultural fields, simultaneously increasing productivity of plant growth and reducing GHG emissions and nitrates in our water. Microbes are the foundation for a more resilient agriculture industry to support farmers as they feed and fuel humanity’s ever-growing needs.

The use and application of these microbes is simple, and they can be used easily as part of a farmers’ current practices. The microbes have a mutualistic relationship with the crop, producing nitrogen and delivering it directly to the roots. These microbes continually feed nitrogen to corn plant throughout the growing season with peak nitrogen production during the crops’ most critical growth stages. The microbes adhere to the roots of the corn plant and will not run off during weather events. This supports a more reliable and consistent method for delivering plant nutrition. 
 


 


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About the Author

Carolyn Fortuna, Ph.D. is a writer, researcher, and educator with a lifelong dedication to ecojustice. She's won awards from the Anti-Defamation League, The International Literacy Association, and The Leavy Foundation. As part of her portfolio divestment, she purchased 5 shares of Tesla stock. Please follow her on Twitter and Facebook.



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