Nitrogen: A Foundational Element

Nitrogen is one of the most important atoms in biology. Every strand of DNA contains nitrogen. It is also present in all proteins and many other critical organic compounds. By mass, nitrogen is the fourth most abundant element in the human body (the top three are oxygen, carbon, and hydrogen).

It also comprises roughly 78% of the Earth’s atmosphere.

All organisms on Earth require nitrogen to grow. However, despite nitrogen’s abundance in the atmosphere, it is often in short supply on land. This is due to the fact that atmospheric nitrogen is unusable for most forms of life. Before photosynthetic organisms can absorb it and transfer it up the food chain, this relatively unreactive element must first undergo certain modifications.

Thankfully, numerous varieties of bacteria are capable of capturing atmospheric nitrogen and transforming it into compounds that plants absorb. Many of these bacteria have evolved close symbiotic relationships with plants. In such relationships, the bacteria use atmospheric nitrogen to create nitrogen-containing compounds that the plants can absorb. In exchange, plants provide bacteria with other forms of nutrients and sustenance.

These nitrogen fixing bacteria produce massive amounts of usable nitrogen every year. Still, modern agricultural operations often remove nitrogen at a rate higher than that which the bacteria can replenish. For this reason, farmers frequently apply nitrogen-containing fertilizer to their fields. While doing so allows for greater yearly yields, it can also create big issues.

Rainfall and irrigation have a tendency to wash the nitrogen from fertilized fields into local watersheds. Once this nitrogen has found its way into aquatic ecosystems, it allows algae to grow at much higher rates than usual. In some instances, the metabolic activity of large nitrogen-produced algae blooms removes so much oxygen from the water that fish and other aquatic organisms perish in large numbers.

These die offs often have huge negative ramifications for fishermen who rely on their catch to make a living.

Aquatic environments aren’t the only systems affected by humans’ tampering with the nitrogen cycle. Our burning of fossil fuels releases nitrogenous compounds into the atmosphere. Once there, these compounds can contribute to the production of acid rain and the exacerbation of the greenhouse effect.

So what can we do?

For one, farmers can use greener methods of replenishing the amount of nitrogen in their soil, such as cover cropping. With this technique, farmers restore the soil’s nitrogen levels by planting crops that foster nitrogen fixing bacteria. Though cover cropping takes a longer period of time to replenish the soil than directly applying nitrogen-containing fertilizer, it is also far easier on the environment.

As mentioned previously, the combustion of fossil fuels releases nitrogenous compounds into the atmosphere. Therefore, switching to renewable electricity generation technologies and electric cars will help keep these compounds out of our air.

If you want to help stabilize the nitrogen cycle, you can do so by purchasing organic food, which is generally produced with fewer fertilizer inputs. Another good measure could be to buy an electric car.

You can also improve the situation by raising awareness, and drawing attention to the fact that the disruption of the nitrogen cycle has significant negative effects on people and the planet.