Nitrogen: Plants Gotta Have It. And So Do We!

Nitrogen: plants gotta have it, as do all other creatures on the planet. That’s because nitrogen is needed by both plants and animals for growth and development. Since the earth’s atmosphere is made up of 78% nitrogen and 21 percent oxygen, one would think that nitrogen would be an easy element to simply breathe in.

Humans and almost all other animals can’t convert atmospheric nitrogen into the form needed to be useful. They need to consume (that is, eat) living things that contain the element in the form of animal and plant proteins.   

How do plants get nitrogen?

That begs the question. Since plants can’t eat, how do they get nitrogen? As I said before, plants gotta have it. They can’t eat it, and like every other living entity, they can’t take it directly from the atmosphere.

Well, certain bacteria live in the soil that can take in atmospheric nitrogen and “fix” it – that means they convert the atmospheric form into a substance that can be used. I’m not going to go into the chemistry, but it is interesting. If you’re interested, search the web.

Once the conversion process is completed, the “fixed” nitrogen, which is now in the soil, becomes available to plants.

And how do plants use nitrogen?

Plants use the “fixed” nitrogen to grow and develop. We and millions of other creatures eat the plants and obtain nitrogen that way. We (and other carnivores and omnivores) also eat the animals that have eaten the plants, giving us the nutrient we need.

If you’ve noticed the process, it is circular and interconnected, like most living and non-living things on the planet.

  1. Bacteria take in the gas, fix it, transfer it to the plants.
  2. Herbivores and omnivores (which includes us humans) eat the plants.
  3. Omnivores and carnivores also eat the herbivores (and sometimes other omnivores and carnivores), which have already obtained it from their food.
  4. The cycle begins again.

At least, that’s supposed to be how it happens. But now we come to the fly in the soup.

The fly in the soup

At the beginning of the Industrial Revolution, a vast population shift took place. The U.S. and Europe were, up until that time, largely rural and agricultural. But the rise of industry caused people to move en masse to industrial centers in hopes of good jobs and a better life.

As a result, there were fewer people to farm and raise livestock. The “elites” of the major nations realized that feeding a growing urban population would pose a serious problem.

Along came Fritz Haber, a German chemist, who, in 1904, developed a way to fix nitrogen directly from the atmosphere and transform it into a way that plants could take in. This was a boon to farmers, but increasing crops wasn’t the only thing on the industrial scientists’ minds. They also found out that nitrogen can make things go boom (re. Hindenburg).

Along comes WWI, and industry found a new way to exploit nitrogen. They could use fixed nitrogen to make –  what else – bombs. After the war, these industries continued making nitrogen products to boost crop yields. Between WWI and WWII, farmers in the Midwest, trying to survive the Great Depression and falling crop prices, used bad farming practices to increase crop production…and unintentionally created the Dust Bowl. Although other bad farming played a much larger part art in the devastation, the use of man-made fertilizers helped disrupt the microbiology of the soil, essentially eliminating the need for nitrogen-fixing bacteria.

The interconnection of nitrogen, soil biotics, and the cycle of life needs to continue. Concern and care of the microbes in the soil is a necessary part of our survival as a species. As my granddaughter says, It’s complicated.