The Alchemy of Nitrogen-Fixation

By Kevin Hancock

With an ever-increasing world population comes an increased demand for food, fuel, and fiber. Land, water, and energy resources are becoming scarcer. Nitrogen is abundant worldwide, and is needed for the growth of most plant species. The majority of the world’s nitrogen is in the gaseous form, which cannot be utilized by most plants. This means that most plants must rely on additions of synthetic fertilizers to supply the needed nutrients.

There are very few plant species that are capable of fixing atmospheric, N2 gas, converting it into a usable form like ammonia, and storing it in root tissue. These plants are referred to as nitrogen-fixing. Symbiotic nitrogen-fixation (snf), which occurs naturally in some leguminous crops, can play a vital role in transforming atmospheric nitrogen gas into ammonia that can be utilized by these plants.

Biological reduction to ammonia can only be performed by prokaryotes and is a highly oxygen-sensitive process. Symbiotic interactions between prokaryote partners occur in two groups of soil bacteria — rhizobia in symbioses in legumes and Frankia bacteria in actinorhizal symbioses.

Snf is highly important in the production of biofuel feedstocks. Many current plants which produce abundant amounts of biofuels such as oil palm, canola, and corn are not nitrogen-fixers and consequently they rely on inorganic nitrogen fertilizers. Every step in the production, delivery and application of nitrogen fertilizer requires fossil fuels. Even though the formation of fossil fuels occurs naturally through anerobic decomposition of plants and animals, they are not considered renewable sources of energy.  Decomposition takes millions of years to form large enough quantities of fossil fuels. Those reserves are being depleted at a much higher rate than they are being formed.

The problem with the use of synthetic fertilizers is that plants only absorb a small percentage of applied fertilizer at any one time. The remainder of the applied fertilizer (30-50%) is subject to runoff, volatilization, and are leached beyond the root zone or denitrified. In many areas this can create algae blooms and eutrophication – a condition of high concentration of nutrients, but low oxygen levels. For example, Lake Okeechobee in Florida is experiencing this due to nutrient runoff from adjacent croplands.

Snf reduces the plant’s dependence on inorganic nitrogen sources and can provide a substitute for nitrogen fertilizers, thus reducing costs and helping the environment at the same time. Biological nitrogen fixation has been estimated to produce approximately 200 million tons of nitrogen annually.

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Leguminous root nodules – PC: NMSU

It would be very beneficial to humanity as well as the environment if all agriculturally important plants were capable of fixing atmospheric nitrogen.  Although a lot is still unknown, a lot of work has been conducted to better understand the intricacies involved in symbiotic nitrogen fixation. Nitrogen-fixation is composed of 3 components; first, the formation of nodules which provide the correct environment for nitrogen-fixing bacteria; second, the regulation of nodule numbers by both internal and external factors, and third, the actual conversion of atmospheric nitrogen into ammonia by the invading bacteria using the nitrogenase enzyme complex.

Nitrogen-fixing plants are not capable of extracting N2 gas directly from the atmosphere, they work in concert with common soil bacteria called Rhizobium. Rhizobia attached to root hairs, induce a pronounced curling of root hair cells. The root hair becomes deformed and the bacteria enter the plant by a newly formed infection thread growing through it. At this same time, cortical root cells are mitotically activated giving rise to the nodule primordium. Infection threads will grow towards the primordium and the bacteria are released into the cytoplasm of the host cells. The bacteria become encapsulated in the small compartment formed by the curling. The bacteria enter the plant’s root system and form nodules along the root pathway. The plant supplies all the essential nutrients as well as energy to the bacteria. Within a week after infection, nodules will become visible by the naked eye. Under field studies, nodules appear within 2-3 weeks. The nodules allow the plant to absorb the N2 gas that is present in the soil, and the plant converts it into ammonia that enters into a biochemical pathway producing both organic and inorganic forms before reverting it to N2 gas. Nitrogen-fixing bacteria need high calcium levels to work efficiently. Three micro-metabolic elements, iron, molybdenum, and cobalt are essential for the nitrogen-fixing process in bacteria.

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Nodule Formation Cycle in Pea Plant – PC: Pearson Education

Most legumes form symbiotic relationships with a select few Rhizobium, however Pongamia pinnata is able to produce snf relationships with various strains of Rhizobia as well as Bradyrhizobium. In areas of India the results clearly demonstrate the major advantage of the leguminous nature of Pongamia when compared to the Jatropha tree, another plant feedstock being evaluated as a source of biofuel energy.

Since the presence of oxygen can inactivate the process of nitrogen-fixing, it is important to know that legumes can regulate the gas permeability in their nodules allowing enough oxygen to maintain respiration without deactivating the nitrogenase enzyme. Nodules contain a heme protein called leghemoglobin. Leghemoglobin is present in the cytoplasm of infected cells at high concentrations (700 uM in soybean nodules). This protein gives the nodule a pink color.

The mystery of the symbiotic relationship is that it only occurs through a complex exchange of signals between specific genes of the plant host and symbiont. Infection and nodule organogenesis occurs simultaneously during root nodule formulation. The symbiotic relationship between legume and bacteria is not obligatory. It is quite possible for a seedling to live out its life cycle without becoming associated with a symbiont.

Among many compelling characteristics, the reduction of dependence on commercial, nitrogen fertilizers, the reduction of runoff and minimizing other environmental concerns all show the benefits of the snf process inherent in Pongamia pinnata.

 

References:

Majda, W. (2014). How to increase the rate of biological nitrogen fixation. Retrieved from https://permaculturenews.org/2014/09/25/increase-rate-biological-nitrogen-fixation/

Meyer, S. B., Anderson, D. B., Bohning, R. H., & Fratianne, D. G. (1973). Introduction to plant physiology (2nd ed.). New York, NY: D. Van Nostrand Company.

Rhoades, H. (2017). Nitrogen nodules and nitrogen fixing plants. Retrieved from https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/nitrogen-nodules-and-nitrogen-fixing-plants.htm

Taiz, L., & Zeiger, E. (2002). Plant physiology (3rd ed.). Sunderland, MA: Sinauer Associates, Inc.

Wikipedia. (2017). Nitrogen fixation. Retrieved from https://en.wikipedia.org/wiki/Nitrogen_fixation

Flynn, R, & Idowu, J (2015) Guide A129 Nitrogen Fixation by Legumes. Retrieved from http://aces.nmsu.edu/pubs/_a/A129/

Market Driven Restoration: Stepping Beyond Sustainability

by Drew Wilkinson, TerViva Propagation Associate

As a farmer, I’m naturally drawn to the diverse array of agriculture solutions that hold potential for making significant strides towards a carbon neutral future. While combing through the spring 2017 issue of Permaculture North America Magazine, I came across an interview that ignited my attention. It was on David Karr, the co-founder of Guayaki Yerba Mate, and featured a unique business model I knew little about, but came to greatly admire. It is called market driven restoration. Karr explains one of their main missions is to “steward and restore 200,000 acres of South American Atlantic Rainforest and create over 1,000 living wage jobs by 2020.”

With their roots planted deep in the soil, I was excited to learn about this company striving to go beyond sustainability. The more I read, the more I reflected on the intricate relationships between consumers, businesses, agroforestry, community, environment, and the resulting impacts on global climate change.

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Rainforest in Paraguay – Photo Credit: Cyrus Sutton

Guayaki specializes in fair trade organically grown yerba mate, an herbal tea made from the leaves and stems of the holly tree, Ilex paraguariensis found in the South American Atlantic Rainforest. Yerba mate has been a long standing cultural drink in Argentina, Brazil, and Paraguay. It’s a healthy alternative to coffee and according to the Guayaki website it includes 24 vitamins and minerals, 15 amino acids, a surplus of antioxidants, and naturally occurring caffeine all which provide a smooth energetic lift. Guayaki sells a variety of yerba mate products ranging from canned drinks to loose leaf.

There are many sustainable components of Guayaki’s business model that set them apart from the crowd. They have a very thought out supply chain that incorporates biodiesel powered cargo vehicles, biodegradable packaging, and chemical free facilities to name a few. They are a certified B Corp, which is a rigorous certification process completed by B Lab, a non-profit that verifies companies meet standards of social and environmental performance, accountability, and transparency. The most impactful part of Guayaki’s supply chain lies within their approach to producing forest grown yerba mate and their ability to sequester 573g of carbon for every 454g of yerba mate produced.

According to Project Drawdown, which describes the top 100 ways to reverse global climate change, Paul Hawken and his team of international scientists and policy makers have ranked the reforestation and preservation of tropical forests as #5 on the list of 100 solutions. Guayaki has incorporated reforestation as a standard for cultivation of yerba mate. The highest quality yerba mate grows beneath the shade canopy of taller hardwoods. As Guayaki expands their agriculture production, they are replanting hardwood trees along with fruit trees to create the perfect environment to grow yerba mate, all the while restoring biodiversity.

A sustainable hand harvesting approach is used to collect yerba mate. Yerba mate produces more income per acre than cattle or agricultural products such as corn, soy, or wheat. Guayaki is able to provide a stable annual living wage for these small farmers, which allows them the ability to plan and make long term decisions about the health of the land and their people, while adding a “market driven” incentive to restore and protect the forest.

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Hand harvested yerba mate – Photo courtesy of Guayaki

Guayaki achieves this by building relationships and working with native forest communities. They help construct tree nurseries, organize grower conferences, and provide safe and just working conditions. The revenue generated from selling yerba mate in North America cycles back to these indigenous communities and helps fund the rainforest restoration. This steers the local economy in a regenerative ideology away from the clear cutting mentality for lumber, cattle grazing, and monocrop agriculture that has eradicated 90% of the South Atlantic Rainforest.

Project Drawdown summarizes that when these tropical forests are restored, “trees, soil, leaf litter, and other vegetation absorb and hold carbon. As flora and fauna return and interactions between organisms and species revive, the forest regains its multidimensional roles: supporting the water cycle, conserving soil, protecting habitat and pollinators, providing food, medicine, and fiber, and giving people places to live, adventure, and worship.”

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Indigeneous workers – Photo courtesy of Guayaki

At the heart of Guayaki’s business model is the principle of internalizing all the true costs. This goes outside the norm of traditional business structures with a narrow minded focus on profit. As companies strive to maximize profits, negative externalities result and are pushed to the side or slid under the rug and out of view from the public eye. As a result, companies end up not paying the full cost of extraction of materials, production, distribution, and disposal. These costs are often felt negatively by 3rd parties in the form of land degradation, excess carbon emissions, toxic waste, and polluted waterways.

Karr summarizes that this ‘short term thinking’ paradigm shifts the true costs of conventional business to future generations. Guayaki’s market driven restoration model serves as an exemplary platform for other companies to strive for. Karr states “We’re passionate about people voting with their dollars. We believe business can drive environmental and social change.”

So, where do we go from here? I encourage you to think about your next purchase as a consumer. Try to incorporate a broader whole systems thinking approach to the product you are purchasing. Instead of just laser beaming your focus on what the product will do for you and the associated lowest price mentality, think about the external costs that may or may not be reflected in the price tag.

While the effects of global climate change are felt across the world, environmentally conscious consumers can help shape more eco-minded businesses, and together we have the potential to play a huge role in shaping a carbon neutral future.

More references:

https://www.nielsen.com/content/dam/nielsenglobal/dk/docs/global-sustainability-report-oct-2015.pdf

https://www.bcorporation.net/what-are-b-corps?gclid=EAIaIQobChMItqbwlaiO1wIVSGV-Ch1Dpwt2EAAYASAAEgL9afD_BwE

What I Wish I’d Known Before Becoming a Pongamia Farmer

by Elisabeth Beagle, TerViva Propagation & Agronomy Associate

My friends won’t know what I’m talking about.

New pongamia farmers, have your elevator pitch ready – even most fellow farmers have never heard of the crop. Pongamia (pohn-gah-me-ah for most, pohn-gaym-ee-ah for Florida folks) is a semi-deciduous, nitrogen-fixing legume tree that can be grown in diverse tropical and subtropical marginal lands. Drought and salinity tolerant, it’s well-suited for land not arable for food crops. The trees grow to 15-20 meters, set flowers after 3-4 years, and take 9-11 months to form a mature pod after anthesis.

Pongamia farmers harvest pods – up to 100 kg of pods per mature tree, per year. Each pod contains a seed. The oil content of the seed is approximately 35% of the dry seed weight and 55% of it is oleic acid, the ideal fatty acid for good-quality biodiesel production. Uses for pongamia oil are extensive – from adjuvant to lubricant, biodiesel to jet fuel. Beyond the oil, the seedcake (pulp left over after the oil is pressed from the seed) is a valuable source of protein; the pod shells separated during processing is a viable baseload feedstock for power plants.

DO mistake the forest for the trees.

Each variety of pongamia tree grows differently – the trick to successful pongamia crop production is to grow the best varieties, consistently. Ideal traits include regular and timely flowering, growth rate, pod set and weight, and seed oil content. Here’s the catch: if you crack open a pod and plant the seed, the tree that grows is unlikely to share the characteristics of the tree the pod came from. TerViva has compiled an exclusive library of high yielding, patentable pongamia genetics from around the world, and developed propagation techniques for scalable, consistent results. The core of TerViva’s IP platform is elite pongamia genetics that are iteratively advanced.

TerViva is not a coconut water company, Mom.

TerViva helps growers convert distressed agriculture land into productive acreage by growing pongamia. The US has lost 40 million acres of arable land in the past 40 years to disease and changing environmental conditions – while demand for food and fuel soars. In Florida, disease has caused 50% of citrus acreage to be lost in 10 years. Hurricane Irma made the picture worse. In Hawaii, 85% of sugarcane production has been abandoned due to cost of production and competition.

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Pongamia orchard on the North Shore of Oahu in July 2017

TerViva provides cultivar development and supply by selling growers elite trees best suited to their situation. TerViva has established commercial size acreage in Florida and Hawaii, geographies where the need for a new crop and the proper climate for pongamia intersect. Pongamia easily “drops in” to existing farm operations, utilizing the same field setups and infrastructure. The grower plants and maintains the trees at their expense; the pods are harvested using existing mechanical nut-harvesting equipment and transported to a centralized processor; then TerViva acts as the marketer for oil, protein seed cake and shells.

Pongamia farmers in Hawaii take an average of 9,740 steps per day in the field.

Hope your boots are made for walkin’, pongamia farmers. It turns out putting hands and eyes on each of the 121 trees per acre adds up to quite a distance. Trees are planted at 18 feet intervals along rows spaced 20 feet apart to accommodate the catchment frame of the harvester. Each field row consists of trees of the same cultivar, so that the entire row flowers, sets pods, and is ready for harvest at the same time.

The walking distance triples during planting. Pray for cloud cover.

Never say there is nothing beautiful in the world anymore. There is always something to make you wonder in the shape of a tree, the trembling of a leaf (Albert Schweitzer).

Sweaty, dusty pongamia farmers enjoy moments of respite while sitting beneath the shade of pongamia trees, reflecting hopefully on the gravitas of our work. Growing pongamia is for those farmers who are in it for the long game; growing pongamia is an investment for the future. Growing pongamia exhibits the belief that agriculture will continue to lead our population forward, towards renewable and environmentally sustainable energy sources. Had I known how rewarding growing pongamia would be, I would have started sooner! Wish someone had told me.

 

 

We Can Reverse Climate Change

by Lila Taheraly

After learning about Project Drawdown last year, I could breathe a sigh of relief. I could finally envision an appealing goal for the world: reversing climate change. Not mitigating it, adapting to it, or solely reducing greenhouse gas emissions, but actually reversing climate change.

Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming is a book which gathers 100 solutions to reduce greenhouse gas emissions and sequester carbon. It ranks them based on their potential carbon impacts in the next 30 years, and studies their implementation costs compared to business as usual (using fossil fuel oil, gas and coal). Published in June 2017, the book describes a possible and hopeful future.

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PC: Paul Morris on Unsplash.com

What is Drawdown? Drawdown represents the moment when greenhouse gas concentrations in the atmosphere begin to decline. Combined, all these proposed solutions could eliminate up to one trillion of tons of CO2 from the atmosphere by 2050 — enough to prevent the climate tipping point of 2 degrees Celsius over pre-industrial level. These solutions would also cost less and create more jobs than business as usual.

Below are the top 10 solutions in terms of carbon impact and their potential carbon savings by 2050:

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PC: Karsten Würth on Unsplash.com

  1. Refrigerant Management – 89.74 GT CO2* eq.
  2. Onshore Wind Turbines – 84.60 GT CO2 eq.
  3. Reduced Food Waste – 70.53 GT CO2 eq.
  4. Plant-Rich Diet – 66.11 GT CO2 eq.
  5. Tropical Forests – 61.23 GT CO2 eq.
  6. Educated Girls – 59.60 GT CO2 eq.
  7. Family Planning- 59.60 GT CO2 eq.
  8. Solar Farms – 36.90 GT CO2 eq.
  9. Silvopasture – 31.19 GT CO2 eq.
  10. Rooftop Solar – 24.60 GT CO2 eq.

Beyond these 10 solutions, the real power of this book lies in the abundance of solutions and the measurement of their potential impact. These technologies all exist today, and some are scaling up right now. In the USA, in 2016, solar power employed more people than electricity generation through coal, gas and oil combined.

To reflect on this profusion of solutions, here is my selection of favorites through an award competition.

The unexpected: Educating Girls, ranked 6th.

Discovering “Educating Girls” as the 6th solution to mitigate Climate Change was fascinating! After the surprise, the explanation made perfect sense. Educated girls tend among others to have fewer and healthier children, to have higher wages and contribute more to the economic growth. In developing countries, educated women also grow more productive agricultural plots, and their families are better nourished. Today, there are still barriers preventing 62 million girls from their education rights.

The low-key: walkable cities, ranked 54th.

Walkable cities or neighborhoods favor walking over driving (thus reduce CO2 emissions but also improve health). In a neighborhood, walkability can include density of homes, offices, and stores; practicability of sidewalks, walkways and pedestrian crossings; and accessibility to public transportation. Today, demand for walkable cities far exceeds the supply. You can check the walkability of any location via applications like this one.

The never-heard of: temperate forests, ranked 12th.

We hear so much about the tropical forest degradation, than we tend to forget its sibling: the temperate forest. A quarter of the world’s forest lies in temperate zone, either deciduous or evergreen. 99% of it has been altered throughout history with timber, conversion to agriculture or urban development. This solution is to restore and protect temperate-forests on degraded land. Young temperate forests sequester carbon in both soil and biomass at very fast rates.

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The most picturesque: in-stream hydro, ranked 48th.

While hydropower reminds us at huge dams, reservoirs, and big environmental impacts, in-stream hydro is defined as less than 10 mega watts hydropower technologies. They are small scale in-stream turbines. The advantage of small scale is that turbines can be designed to have a minimal impact on the environment and become accessible in remote territories like Alaska or Nepal, unlocking great potential.

The most related to our business: perennial biomass, ranked 51st.

Compared to annual crops like corn, perennial biomass grows for many years. In a climate perspective, it makes a fundamental difference. Perennial biomass throughout their lifetime requires fewer energy inputs, and prevents soil erosion, produces stable yields, supports pollinators and biodiversity. As an example, Pongamia, an oilseed producing tree, is a legume and fixes nitrogen naturally.  Pongamia also grows deep roots thereby reducing water needs and increasing the carbon sequestration.

My  favorite coming attraction: living buildings

Besides 80 solutions against climate change, Project Drawdown also introduces 20 “coming attractions”. One of them is “Living Buildings”. Living buildings answer the question: How do you design and make a building so that every action and outcome improves the world? For example, Living buildings could grow food, use rainwater and protect habitat. The Brock Environmental Center in Virginia Beach, VA, completed in 2014 produces all of its drinking water from rainfall, uses 90% less water than a commercial building of the same size, and generates 83% more energy than it consumes.

Curious and inspired by Project Drawdown? You can visit their website, read the book, and come back to tell me about your favorite solutions.

 

 

 

 

*Note: 1 gigaton of CO2 (GT) = 1,000,000,000 tons of CO2.

At ambient temperature, one ton of CO2 holds on in 559 cubic meters (19,775 cubic feet), i.e. in an 8.25 m high cube (27 ft).

 

 

 

From Inside the Pipeline: Energy & Ag in Hawaii

By Marie O’Grady, Elemental Excelerator Communications Coordinator

Exhaust poured from the truck as it came to a grinding halt at the base of a conveyor belt, delivering Hawaiian Commercial & Sugar Company’s last cane harvest, symbolizing the end of an era in Hawaii. As happened in Puerto Rico and Trinidad & Tobago, growing sugar in Hawaii was no longer profitable.

In early 2016, Alexander & Baldwin (A&B), the fourth largest land owner in Hawaii, announced the close of Hawaiian Commercial & Sugar Company (HC&S), the state’s last large-scale sugar plantation. Over the years, HC&S had faced controversies around water, pesticides, and field burning, and in 2015, the company incurred a $30 million operating loss.

Alexander & Baldwin announced in early 2016 that all 36,000 acres of former HC&S land would be transitioned to diversified agriculture, such as energy crops, agroforestry, livestock, diversified food crops, and orchard crops. Last month, A&B announced a new partnership with TerViva to cultivate pongamia on 250 acres of former plantation land.

EEx TerViva - orchard - 1

We believe pongamia can help diversify agriculture production on Maui while also potentially addressing our community’s need for renewable fuels. Our former sugar lands provide a great opportunity to grow more energy crops locally as they are ideally suited for large scale cultivation and mechanical harvesting.” – A&B President & CEO, Chris Benjamin

TerViva was the first ag company to join Elemental Excelerator’s portfolio in 2014. As part of their demonstration project, they are growing more than 200 acres of pongamia trees on Oahu and Maui. The oil extracted from pongamia seeds is well suited for industrial applications such as biopesticides, lubricants, chemicals, and fuels – and the residual seed cake shows promise as a feed supplement for beef cattle. Compared to soy, pongamia requires only 25 percent of the chemical and water inputs. One acre of pongamia produces 10 times more oil and 3 times more protein rich seed cake than one acre of soybeans.

EEx TerViva 3

This project is not only transformational for TerViva (it’s their first orchard in the region), but it’s also transformational for Hawaii.

  • Local farmers and agribusinesses are a critical source of economic stability for rural economies, through jobs and direct and indirect spending. TerViva is steadily growing its Hawaii-based team, and the company supports two local nurseries and a handful of contractors.
  • Pongamia is able to grow on marginal agricultural land that is not suitable for other crops. This is ideal for a place like Hawaii where the soil, which once provided resources for thousands of acres of sugarcane and pineapple, has been largely stripped of key nutrients.
  • Biofuel and biomass play a role in Hawaii’s transformation to clean energy, providing firm, dispatchable power. Hawaiian Electric’s December 2016 Power Supply Improvement Plan outlines how the utility plans to utilize biofuels in power plants to replace oil as a fuel source.

There is a growing trend in the number of new agtech companies mature enough for a demonstration project, as evidenced in Elemental Excelerator’s pipeline of applicants:

  • Since 2014, EEx had added four other agriculture startups to the portfolio of 53 startups. These companies are working to increase local beef production, increase crop yields, and help small farmers use data to reduce water usage.
  • Over the last few years, EEx has also seen a dramatic increase in applications from ag startups. This year, 10 percent of the companies who took the first step to apply were agriculture-related. That’s twice as many as last year!

After Monsanto acquired the Climate Corporation in 2013, ag tech gained significant attention. In 2014 alone, investments in ag tech grew 170%. Most innovation was focused in the areas of biotechnology and seed genetics. Today, subsectors include bioenergy, sustainable protein, decision support tech, soil & crop tech, advanced imaging & data analytics, and many others. Investment and innovation are no longer limited to players in the agriculture sector. Moreover, as concern grows over droughts, weather fluctuations, the cost of farm labor, and competition with international markets, key players such as farmers, agro-businesses, and landowners are searching for ways to grow smarter.

 

Elemental Excelerator

Elemental Excelerator helps startups change the world, one community at a time. Each year, they find 12-15 companies that best fit their mission and fund each company up to $1 million to improve systems that impact peoples lives: energy, water, agriculture, and transportation. To date, Elemental Excelerator (EEx) has awarded over $20 million to more than 50 companies. What makes EEx unique? They co-fund, co-design, and co-develop projects and strategies that improve infrastructure and sustainably enhance communities. The program is funded by a diverse coalition of utility partners, corporate partners, the U.S. Navy, the U.S. Department of Energy, state government, and philanthropic organizations, and is structured as a non-profit created in collaboration with Emerson Collective.

 

Related articles:

2015 State Ag Land Use Baseline Data, Hawaii Department of Agriculture

AgTech Is The New Queen Of Green, TechCrunch

Cultivating Ag Tech: 5 Trends Shaping The Future of Agriculture, CB Insights

Hawaii’s Last Sugar Plantation Finishes Its Final Harvest, NBC

Fixing Nitrogen, Waste

By William Kusch

irina-sorokina-253176footprint grass

Figure 1: What is your nitrogen footprint?

You may be familiar with the concept of carbon footprint, but when was the last time you measured your nitrogen footprint? If you are like me, up until very recently, the answer to that question would be: “huh?”.

I got to thinking about the topic when I read an article[1] that National Public Radio (NPR) published, profiling research on life cycle analysis (LCA) of producing a loaf of bread. The article concluded that 66% of greenhouse gas emissions were not from transportation, or baking, but from growing the wheat itself.  Further, “of the environmental impacts … 40% is attributable just to the use of ammonium nitrate fertilizers alone.”

Intrigued, I read on, re-read my colleague’s excellent blog post on animal and livestock nutrition, then clicked my way to a related article[2], also on NPR that dove deeper than greenhouse gas emissions. This story looked specifically at the nitrogen pollution linked to agriculture, with an emphasis on meat production. This piece outlined some agricultural sources and forms of this significant pollutant:

  • Gaseous emissions of nitrogen oxides (NOx) from livestock
  • Release of N2O, and NOx from soil microbes
  • Runoff from excess fertilizer applied to farm fields.

Well, you may say, so what? Isn’t most of the air we breathe nitrogen anyway?  While it is true that a large majority of the atmosphere is nitrogen, it comes in the form of inert N2. N2 is far different from N2O and NOx , two recognized pollutants. Here are a couple of the potential implications from the release and accumulation of N2O and/or NOx:

  • WK gulf mexico

    Figure 2: Image depicting marine dead zone in Gulf of Mexico

    Marine dead zones, such as the famous one in the Gulf of Mexico, where most ocean life has died due to lack of oxygen[3]

  • If concentration is elevated in drinking water, can lead to potentially fatal blue baby syndrome, other negative health impacts[4]
  • Emissions of NOx can lead to the hazardous type of ozone that remains near ground level. This type of ozone can trigger health problems, especially for children and the elderly[5].

Given that agriculture is one of the biggest contributors to nitrogen pollution, and also that no one is going to stop eating in order to stop polluting, what can people do to reduce their nitrogen footprint? Fortunately there are some simple, and effective options to pare the amount of nitrogen pollution associated with our daily activities:

  • Average Americans “eat about 1.4 lbs of protein per week, 2/3 of which come from meat and dairy. …you could cut your nitrogen footprint by more than 40% just by reducing your total protein intake to 0.8 lbs, the amount recommended by the USDA and the National Academy of Sciences”.
  • Get creative with your spending power: think about ways you could change one meal a week from animal protein to one that is centered around plant protein such as that from chickpeas, or assorted beans.
  • Throw away less of your food: an estimate from Natural Resources Defense Council[6] indicates that America wastes ~40% of our food by throwing it in the garbage prematurely, or unnecessarily.
  • Encourage your legislators to support agricultural land conservation efforts, especially in areas where plants filter fertilizer runoff before it enters the local watershed.
  • Consider a more fuel efficient, or electric vehicle when choosing your next set of wheels: while agriculture is the largest source of N2O, transportation also accounts for a large share of NOx[7].
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Figure 3: Nitrogen-fixing pongamia trees in TerViva’s Hawaii orchard

At TerViva, we’re doing our part to mitigate this global nitrogen problem as well. We are growing orchards of pongamia: oilseed-producing trees that are legumes and harness the power of symbiotic bacteria to capture nitrogen from the atmosphere. This ability to provide nitrogen for itself allows pongamia to be cultivated using significantly fewer costly inputs relative to most conventional crops, like nitrogen fertilizers. After we harvest the seeds, we crush the crop in an oilseed press, yielding oil and seed cake. The oil serves as an excellent feedstock for biofuel. The seed cake is high in protein and we have discovered how to convert the pongamia protein into animal feed. In addition to feeding livestock, pongamia seed cake can also be used as a fertilizer[8]; we know this because people have been using pongamia cake as fertilizer in Southern and Southeast Asia for many hundreds of years. The reason this anecdote is relevant here, is that modern scientific techniques have recently been brought to bear, analyzing and quantifying the value of pongamia seed cake as fertilizer. In fact, in addition to demonstrating the value of pongamia products as fertilizer, recently published research shows that if pongamia seed cake is used as a fertilizer, there are compounds in the fertilizer that prevent nitrogen pollution from happening in the first place when farmers apply fertilizer to their fields [9].

Through this idea of considering our Nitrogen Footprint, we at TerViva are exploring ways that we can provide renewable, plant-based energy and protein to society, while at the same time preventing and mitigating some of the issues that arise from the modern lifestyles that afford us comfort and convenience.

References:

[1] http://www.npr.org/sections/thesalt/2017/02/27/517531611/whats-the-environmental-footprint-of-a-loaf-of-bread-now-we-know

[2] http://www.npr.org/sections/thesalt/2016/02/25/467962593/why-your-hamburger-might-be-leading-to-nitrogen-pollution

[3] http://www.noaanews.noaa.gov/stories2015/080415-gulf-of-mexico-dead-zone-above-average.html

[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1638204/

[5] https://www.epa.gov/ozone-pollution

[6] https://www.nrdc.org/sites/default/files/wasted-food-IP.pdf

[7] http://www.pnas.org/content/100/4/1505.full.pdf

[8] http://oar.icrisat.org/424/1/IndJourFer5_2_25-26_29-32_2009.pdf

[9] http://nopr.niscair.res.in/bitstream/123456789/5647/1/NPR%207(1)%2058-67.pdf

Well Managed Animal & Livestock Nutrition As Part Of A Low Carbon Future

by Eduardo Martinez

eddie blog picture

Of many discussions around Global Warming and the subject of greenhouse gas emissions (GHG), the majority are focused on causes like energy production or transportation emissions, and most of those emissions are carbon dioxide.  According to EPA’s 2016 Report, Inventory of U.S. Greenhouse Gas Emissions and Sinks, electricity production and transportation produced over 56 percent of the greenhouse gas emissions in the United States.

In addition to those well known causes, agriculture and livestock production also contribute significant amounts of greenhouse gas emissions.  The three main GHG emitted by the agriculture and livestock sector are nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) emissions, as well as losses of nitrogen (N), energy and organic matter that undermine efficiency and productivity in agriculture.

The greatest opportunity for reduction of GHG emissions in the livestock sector lie with improving the efficiency with which producers use natural resources (think tractor fuel) engaged in producing plant protein for animal production, to manage the cost per unit of edible or non-edible output. These improvements are always being pursued in the interest of increasing yield, enhancing quality, or reducing production costs, all while providing a safe and affordable food supply to the public.

There is an obvious and direct correlation between GHG emission and carbon intensities and the efficiency with which producers use natural resources. But among possible opportunities for reducing GHG emissions, fascinating breakthroughs lie in improving livestock nutrition efficiency at the unit level—in this case—the cow level. The average cow emits around 250 liters of methane per day and ruminants overall (animals like cattle, goats and sheep) contribute about 25% of all anthropogenic or man-made methane emissions.

Today universities and industry are working closely together in many ways to improve cattle production and efficiency by eliminating waste, applying the latest enzyme research to improving ruminant digestion and protein conversion. They are also introducing alternative forms of plant protein that might also be more sustainable than traditional energy-intensive animal feedstocks like soy or corn.

For example, recent studies have identified how livestock diet can affect or minimize methanogenesis — methane production.  One common misunderstanding on playgrounds across America is that the back end of the cow is the prime offender in producing GHG in the form of methane. But the truth is the vast majority of methane comes from the cow’s burp—over 95%, in fact!  Thus the opportunity for improvement lies earlier in the animal’s digestive tract.

Rocky De Nys, Professor of aquaculture at James Cook University in Townsville, Australia, has been studying the effects that introducing seaweed to a cow’s diet can have on methane production.  Specifically, Professor De Nys and his team discovered adding a small amount of dried seaweed to a cow’s diet can reduce the amount of methane a cow produces by up to 99 per cent.  The species of seaweed is called Asparagopsis taxiformis, and JCU researchers have been actively collecting it off the coast of Queensland.

“We had an inkling that we would get some success from this species, but the scale or the amount of success and reduction we saw was very surprising,” he said, adding “methane gas was the biggest component of greenhouse gas emissions from the agriculture sector.” The key aspect of Asparagopsis taxiformis is that it produces a compound – bromoform (CHBr3) – which prevents methane production by reacting with vitamin B12 at the final step, disrupting enzymes used by gut microbes that produce methane gas as waste during digestion.

Advances such as these are critical to increasing sustainability in the farm and livestock industry and reducing the carbon intensity of farming and producing our global food supply.  TerViva is providing forward thinking solutions in the form of our tree-based platform for producing plant protein and vegetable oil, Pongamia pinnata.

TerViva’s Pongamia tree produces 3 times the plant protein per acre than soy (3 tons vs 1 ton) and 10 times the vegetable oil per acre than soy (400 gal. vs 40 gal.) and all without the negative environmental impact and carbon intensity of annual row crops. Permanently installed orchard crops like Pongamia trees provide tremendous opportunities for carbon sequestration that offset anthropogenic GHG starting with the obvious visible form of the tree visible to the eye, and also from the deep and stabilizing root system below ground.  Pongamia is also a nitrogen fixing legume that takes atmospheric Nitrogen and returns badly needed (N) to the soil.

In the next 12 months, TerViva will be modeling the exact amount of carbon sequestered by our trees per acre, and therefore, the exact amount of carbon reduction that our protein meal offers as compared to soybean.  I’d bet that we’ll find our protein meal offers a compelling advantage over soybean meal in terms of greenhouse gas reduction overall.

Add these sustainable characteristics to the numerous high value products that Pongamia trees yield, and to top it off, a nice shady canopy to host a songbird’s nest or to provide some welcome shade to cattle or sheep on a hot, sunny day and you’ve got a winning addition to tomorrow’s sustainable farming portfolio.