The Nitrogen Predicament: Why Agriculture’s Got To Change

with 6 comments

Lauren Welker:

Geologist, gardener, epicurean, homesteader, scholar, problem solver

Nitrogen (N2) is an essential nutrient for all living organisms, and it’s one of the most important nutrients needed for plant growth. Without it, plants are unable to produce complex organic molecules like amino acids, proteins, and nucleic acids.  For something that comprises 78% of the Earth’s atmosphere – and is so critical to living organisms – one would think plants and animals wouldn’t have a problem obtaining nitrogen. However, it turns out life can only absorb nitrogen once it’s “fixed” – meaning, confusingly, “broken apart” – and bonded to another element.

It’s almost miraculous that we have life at all on Earth, because nitrogen fixation can only occur two ways: lightning and bacteria. The energy from the lightning has the ability to rip N2 apart, allowing the freed nitrogen to bond to oxygen molecules and form NO3– (nitrate) which then rains down on plant life.

Particular types of bacteria in the soil can fixate nitrogen via respiration (energy production). One of the easiest ways farmers facilitate this process is by planting legumes, which have a special symbiotic relationship with the bacteria Rhizobium. Tiny microorganisms can do the same thing as lightning – how cool is that?

The nitrogen absorbed by the plants is passed through the food chain to animal life, and then put back into the soil and atmosphere through animal waste and the decomposition of plant and animal matter – this is totally that Circle of Life Mufasa was talking about.

Nitrogen is also an import element in fertilization for farmers, because nitrogen speeds up plant growth and increases production. Due to the complicated process I described above, you can imagine that it was very difficult to have large scale farming operations before the 20th century. In 1909, the German chemist Fritz Haber discovered how to fix atmospheric nitrogen in the lab. He then worked with Carl Bosch, another German chemist, to fix nitrogen on an industrial scale and created the Haber-Bosch process. This was HUGE. It was such a feat of science that they won the Nobel Prize for Chemistry in 1918.

Haber and Bosch didn’t know it at the time, but they completely revolutionized agriculture. Man was no longer reliant on natural phenomena to grow crops, and with the population boom of the industrialized revolution, we now had a solution to feed a growing, hungry population: nitrogen-based fertilizers.

As with most scientific advancement, it’s difficult to determine the long term effects of a new technology, but we now know that it probably wasn’t the best idea for man to mess with the Nitrogen Cycle via the Haber-Bosch process.

We’re relying on a finite resource to feed our nation: To fix nitrogen in an industrial lab, you combine atmospheric nitrogen and hydrogen to form anhydrous ammonium a.k.a ammonia – the foundation for all synthetic nitrogen fertilizers. The hydrogen used for this process is extracted from fossil fuels, mainly natural gas. Natural gas is very difficult to transport, so the fertilizer is typically produced near the natural gas source. Since it’s less expensive to purchase fertilizers overseas, the United States imports over half the nitrogen-based fertilizer it needs, thus consuming even more fossil fuels in the process. Not only is our price of food now dependent on the price of oil and gas, but what will we do when we’ve drilled that last well?

Damage to Human Health and the Environment: The overuse of nitrogen-based fertilizers has already caused a significant amount of damage. Synthetic fertilizers destroy the delicate nutrient-producing ecosystem in the soil, so farmers have to fertilize more frequently. Not all of the nitrates are absorbed by the plants, and these particular nitrates are purposely highly soluble in water, so the excess nitrates easily wash into various water bodies, then into the oceans, and can cause monstrous algae blooms in coastal waters.


These algae bloom draw-down oxygen from the water and create dead zones. These dead zones can fluctuate by thousands of miles, leaving little time for sea-life to swim away before they suffocate – often leading to massive fish kills. Largely due to all the nitrogen-based fertilizer run-off in the Mississippi, the Gulf of Mexico has the largest dead zone in the world.

Additionally, we also have problems with nitrogen-based fertilizer affecting our drinking water and air. Elevated levels of nitrate in drinking water has been linked to thyroid cancer in adults; however, it’s particularly dangerous for infants. Infants are highly susceptible to nitrate poisoning which causes methemoglobinemia, commonly known as “blue baby syndrome.” There are even studies linking elevated nitrates in water to increases in sudden infant death syndrome cases. Nitrogen-based fertilizers also contribute to particulate matter air pollution, which is linked to respiratory illnesses and cancer.

So are nitrogen-based fertilizers really needed to feed a growing population? According to a 30-year study done by the Rodale Institute – no.  When compared to conventional crops, organic crops had the same, if not higher yields of produce and outperformed conventional crops environmentally and economically. The United Nations also released a report this past spring, stating that by using agroecological processes (relying on the natural environment, such as beneficial trees, plants, animals and insects to fertilize and protect crops) global food production could double in the next 10 years.

A lack of available nutrients for crop production is not the problem – it’s our current agricultural system that needs to change. By utilizing new and old technologies, scientists and farmers have found ways to organically produce high-yielding crops that can feed a rapidly growing population. It’s now up to us to implement agroecological methods in our agricultural system. Of course this is more easily said than done, but you as a citizen and consumer can make a difference. Contact your representatives and inform them of this issue, elect officials that are mindful of the environment, and most effectively – use your purchasing power.  Every time you are at the register you are casting a vote. The more consumers opt to buy local, organic, naturally and sustainably grown food, the less incentive industry has to use synthetic agrochemicals, GMO seeds, and utilize unsustainable farming methods. Consumers have the power to build and destroy entire industries – keep this in mind the next time you’re debating whether to pay a little more for local, organic produce. Those $0.99 conventional peaches cost more than you may think.

6 Responses

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  1. actually algae consume CO2 and release oxygen. so they are pretty green indeed. nice algae monster picture.

    S Fallon

    July 29, 2011 at 3:31 pm

    • You are correct! Algae produce oxygen in the daytime via photosynthesis; however, during the night they continue to undergo cellular respiration and can therefore deplete the water column of available oxygen. Additionally, when algal blooms die off oxygen is further consumed during bacterial decomposition of the dead algal cells. Both of these processes can result in a significant depletion of dissolved oxygen in the water, creating hypoxic (low-oxygen) conditions.

      Essentially, it’s too much of a good thing.


      August 1, 2011 at 8:19 pm

  2. Ms. Welker,

    This is a great first step to talking about the extremely frightening imbalance of reactive nitrogen in the environment but there are some issues I think are worth noting here where I think you can bolster and better inform the discussion. Firstly, all of the evidence of nitrate-nitrogen affecting humans was out of one journal. PubMed is great but it would not fly in academics. Im not disagreeing with what is said, Im just saying that If I were a policy maker (or a farmer for that matter) I would have a hard time being convinced. The evidence that those studies have gained little traction is demonstrated by the fact that we are producing more synthetic nitrogen than ever before in human history with no end in sight. J.N. Galloway has written some really interesting peer-reviewed articles examining world nitrogen balances while Mark David, Laurie Drinkwater, and others have done some great work getting a better understanding of where and how nitrogen is moving off farmland on the Mississippi watershed. Also, Catherine Badgley has done commendable work scouring and examining the scientific literature to discover whether or not organic agriculture can actually feed the world. My personal answer is yes, but with a great number of caveats at this point. The one that comes to mind first is that conventional ag has enjoyed the benefits of 100 years of plant breeding and agronomy while organics has not. Please keep up the good work but please please please, dont let dogma cloud the conversation in the way it has for decades. We need to start fighting fire with fire if we are to make significant changes in policy and economics that go beyond any border and effect billions of dollars and billions of people. Good intentions do not grow food.

    Matthew Brown

    August 2, 2011 at 12:43 pm

  3. Thank you, Ms. Welker.
    I hope the newsmedia pick up your simple, concise account of the downstream costs of our petroleum-enabled industrial food system.
    I hate to think we’ll have to run out of fossil fuel energy inputs before we do anything substantial about the way we grow our food.


    August 3, 2011 at 11:30 am

  4. […] guest posts by Lauren: The Nitrogen Predicament and Somethin’s Gotta Give) Share […]

  5. […] Reposted from […]

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