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].
WK orchard

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.











It’s A Farm-Over: Walmart’s Admirable Ambitions in Sustainable Agriculture

Few corporations evoke envy or ire as much as Walmart.  In my opinion, one area where Walmart is making significant positive impact is in agriculture. In June 2010, Walmart announced a strong commitment to sustainable agriculture, in support of its broader leadership on a variety of environmental issues (

Walmart’s sustainable agriculture initiative has three focal components:

(1) Support farmers and their communities

(2) Produce more food with fewer resources and less waste

(3) Sustainably source key agriculture products

Walmart can rightly claim some success from its sustainable agriculture program.  A few highlights:  monitoring of the beef supply chain in Brazil to avoid deforestation for grazing or soybean cultivation; achieving third-party sustainability certification of 75% of in-store seafood.

“Wait, wait, you expected the Fresh-Over to help farmers?”

“Wait, wait, you expected the Fresh-Over to help farmers?”

But not all initiatives have gone perfectly. For example, an effort to double the amount of locally grown produce in Walmart stores (from 4% to 9%) was recently achieved, a few years ahead of schedule.  However, the benefits to small- and medium-size farmers have been questioned (; some farmers claim that Walmart is squeezing them on prices (shocking).

Recently, Walmart announced what I think is its most ambitious and important agriculture initiative to date:  fertilizer optimization for commodity agriculture grains (corn, soy, wheat) used in third party products on Walmart shelves (e.g., Kellogg cereal).  From the Walmart website:

Corn Flakes“Walmart depends on the American farmer to efficiently produce the key ingredients in many of our products and we want to do our part to help ensure this productivity continues.  You cannot grow food without fertilizer and it is a crucial component of our food supply.  However, over or improper use can negatively impact the environment and the grower’s pocketbook, making it a potentially costly element in food production.  The supply chain needs food companies (our direct suppliers) to signal unified interest, support, and demand for programs, tools, and information that can help producers continuously improve and optimize their fertilizer use, yield, and profitability.  That’s why we have directly engaged a dozen food categories and even more suppliers in a consistent, coordinated fashion to connect our suppliers to their farmer-partners and improve cost effectiveness, as well as helping them meet their own sustainability goals in ways they cannot do alone.”

This initiative reaches as deep as it sounds: Walmart is asking its suppliers to go to its suppliers to go to its suppliers to go back to the field and initiative fertilizer optimization protocols.  Walmart has created a framework to achieve the desired results (, using the very cool “Fieldprint Calculator” tools developed by the non-profit, Field to Market (

I’m guessing the Lake Erie algal blooms don’t help Walmart’s sustainable seafood initiative.

I’m guessing the Lake Erie algal blooms don’t help Walmart’s sustainable seafood initiative.

Why target fertilizers?  That’s a topic for another post, but in short:  fertilizers represent a significant portion of total agriculture production costs and fertilizer run-off has long been responsible for water quality issues.  In just the past few years, we have seen fertilizer run-off contribute to epic algal blooms that in turn wreck havoc on marine ecosystems.  For some startling imagery and links to more info, check out this National Geographic article: .

This Walmart fertilizer initiative is not the first time that it has pushed down on the agricultural supply chain to drive change.  In 2011 Walmart announced that by 2015 it would use only RSPO-certified sustainable palm oil in its private label products (  This may sound straightforward, but it’s quite complicated.  Palm oil is present in 50% of Walmart’s products. And yet, Walmart only uses 84,000 tonnes of palm oil (25M gallons), or only half a percent of global palm oil consumption — not exactly a massive amount – thereby limiting Walmart’s ability to influence in palm oil industry. On top of all of this, it’s not like consumers are clamoring for sustainable palm oil in their Great Value detergent.

Great ValueI view the nitrogen initiative as even bolder, given that Walmart is asking its suppliers (e.g., Kellogg) to increase nitrogen use efficiency for their respective products (as opposed to just for Walmart’s own products, like in the palm oil initiative). Walmart estimates that its suppliers can positively impact 10M acres of corn soy and wheat by 2020 (today in the US there are about 240M acres combined for all three).

Walmart should be commended for its efforts in agriculture sustainability.  They are bringing about real, difficult change.  They are not just looking to buy credits for sustainable palm oil (, they are actual buying segregated “clean” palm oil.  They are not just buying organic produce, they are demanding reductions in fertilizer use for regular food products.

One area where I would like to see more Walmart engagement:  biofuels, which is the intersection of agriculture and energy.  Walmart has already made an ambitious commitment to power its buildings with 100% renewable energy by 2020 (  Walmart operates one of the largest trucking fleets in the world and is consequently a large consumer of diesel fuel.   If Walmart combines its expertise in in sustainable agriculture with its commitment to clean energy, the impact could be huge. I can think of a company that would like to have a role in that initiative.

Naveen is the CEO of TerViva.  He can be found frequenting the snack food aisle of his local Walmart.