I recently read this brief history of the use of nitrogen fertilizer, and it was so interesting to learn more about this crucial agricultural input! In my agricultural economics classes, we often use nitrogen as an input for our examples, so it was good to beef up my knowledge about it. Maybe you will discover a couple of new-to-you facts as well?
Image attribution: By Cicle_del_nitrogen_de.svg: *Cicle_del_nitrogen_ca.svg: Johann Dréo (User:Nojhan), traduction de Joanjoc d’après Image:Cycle azote fr.svg. derivative work: Burkhard (talk) Nitrogen_Cycle.jpg: Environmental Protection Agency derivative work: Raeky (Cicle_del_nitrogen_de.svg Nitrogen_Cycle.jpg) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
(All facts, unless otherwise linked, are from this article here).
- What we should actually talk about when we talk about fertilizer is nitrate – plant-available nitrogen – as opposed to atmospheric nitrogen (N2), which is joined together so tightly that it can’t be used as a nutrient by plants.
- Transforming nitrogen into nitrate has been a challenge for farmers for centuries and been accomplished through the use of manure and composting crop waste. As you can see in the above image, the organic fixation of atmospheric nitrogen and the number of steps involved until you reach nitrate (over decomposition, ammonification, nitrification, and assimilation) is highly complex. Thus, nitrate has actually been a rather scarce resource for most of agricultural history.
- That is, until 1909, when the German chemist Fritz Haber discovered a process that could directly transform atmospheric nitrogen into plant-available nitrate using a high-temperature, energy-intensive process. This is today known as the industrial fixation of nitrogen, or the Haber-Bosch process.
- It is estimated that half of the protein within human beings is made of nitrogen that was originally fixed by this process, whereas the other half comes from the organic cycle of nitrogen-fixing bacteria and archaea. (Side-note: isn’t that a crazy fact?)
- This development, which was able to produce ammonia from air, proved to be the starting point of synthetic nitrogen fertilizers and was a huge shift in the trajectory of food production. But not only that – it was also of high interest for the militaries involved in World War I, since it gave Germans the possibility to produce nitric acid, a precursor to munitions. These chemical processes were also widely used – and thereby perfected – in the European and US munition industry during World War II.
- By the end of World War II, the US had built 10 large-scale nitrate factories in order to make bombs, but no more bombs were needed. Yet, with European and Japanese factories in ruins, the US had a quasi-monopoly on nitrogen production. The former-munition industry thus quickly moved into the production of nitrogen fertilizer and the US became a country whose agriculture relies very heavily on synthetic nitrogen fertilizer, especially because the new hybrid strands of corn that emerged were particularly dependent on high fertilizer application.
- However, applying massive amounts of fertilizer that cannot all be taken in by plants can cause great environmental damage. This process is known as leaching. It can cause huge “dead zones” in river deltas where algae take up all the ecosystem space and prevent other marine life from existing (I am preparing a separate post on that topic). Also, if nitrate leaches into the groundwater, it can be a severe human health hazard: elevated levels of nitrate in drinking water can cause nitrate poisoning (or “blue baby syndrome”) in infants, where the baby’s blood loses its oxygen-carrying capacity.
- One of the reasons environmental protection agencies such as the EPA are so concerned about the levels of nitrate-nitrogen in drinking water and enforce it is because once a water source is contaminated, it is very costly to remove the nutrient from the water – conventional drinking water processing is unable to remove nitrate and thus expensive specialized treatment facilities are needed.
- Despite it being a topic of huge debate in the US, I was surprised to see that the US agricultural industry is actually not the greatest global consumer of nitrogen fertilizer products – according to this presentation, 31% of global nitrogen consumption takes place in China, 16% in India, 11% in the US, 3% in Brazil and the final 39% is distributed among the rest of the world. According to the same presentation, the world nitrogen consumption is forecast to continue its steady increase to 110 million metric tons (!) in 2012/2013.
- However, there are alternatives – as you can see again in the nitrogen-cycle picture above, the use of leguminous plants has been used for centuries in rotation cropping to increase the nitrate level of soils naturally. In fact, this is because leguminous plants live in symbiotic relationships with bacteria that are able to fix nitrogen as organic nitrogen and furnish it to other bacteria that transform it as seen above. This process has been shown to be more environmentally sustainable and equally profitable as the industrial agricultural process.
Bonus: I haven’t had time to listen to it, but this BBC documentary about “Fixing the Nitrogen Fix” sounds really interesting if you have a spare half hour of free time.
Reblogged this on Science on the Land and commented:
argylesock says… The Haber-Bosch process changed the world so much.
Reblogged this on antilandscaper.
Reblogged this on GreenSky.
Thanks for the link to the BBC programme. I haven’t watched it yet but look forward to doing so when I have a spare half hour. Environmental history of nitrogen fixation must be very interesting and something that is not covered in much depth – going to ask my environmental history tutor about this.
Ooh that sounds like a fascinating class! Make sure to report any interesting findings back if you have the time 😉
Will do. Listening to your link programme at the moment. Learning a lot!
Reblogged this on Rashid's Blog.
The nitrate story may have another angle too. I believe dietary nitrate, as well as being responsible for blue baby syndrome, can also be converted to nitrosamines, which are carcinogenic. So 110 million tons a year sounds like a bad plan!
I learned a lot about nitrogen fertilizers from the book Fatal Harvest. I did not know that fertilizer companies use industrial waste to produce fertilizers so while yes, there is nitrogen, there are also heavy metals and who knows what – they aren’t required to disclose all the other stuff, just the elements.
Just like nutritionism, we rely too much on the individual nutrients and don’t really understand the system.
If I remember correctly, synthetic fertilizers kill off the nitrogen fixing bacteria rendering soil tests misleading. Organic soil may test lower than recommended for nitrogen yet perform much better anyway because of the healthy attributes of the bacteria.
Synthetically fertilized soils do not have the bacteria and also lose their ability to retain water over time. Healthy soil holds water like a sponge thereby not being as parched by drought.
I’ve read on conventional farmer’s message boards concern about the general population learning about synthetic fertilizers making it difficult and/or expensive to obtain soon.
Too many issues…
Oh that is fascinating about synthetic fertilizer killing off nitrogen fixing bacteria! Isn’t it funny that the more research and technology we have available in agriculture, the less the majority of farmers seem to understand (or care for, or act in accordance with) the natural processes? I’ve been reading a selection of Wendell Berry’s works and he already advocated for the sustainability and profitability of farmers that stick to a natural production process in the 70s and 80s. But so little people listened to what he had to say..
Now that I think of it, I’m not sure if it’s the fertilizer or the pesticides, or the combo of all that strips the soil, but I suppose it doesn’t matter. One always follows the other… It’s been a while since I read Fatal Harvest – time to revisit.
Nice post – I like no. 4, bacteria are so important in so many processes!
When I read it, it was like ‘The Circle of Life’ started playing in my head or something. Brings a whole new meaning to the phrase ‘we are what we eat’…
Reblogged this on Natural Living Mamma and commented:
This is an awesome post about nitrogen and how it naturally occurs in soil. We plan on planting a lot of legumes this year, not because we eat a lot of them, but because they fix nitrogen in the soil. I am loving this explanation by Food Policy For Thought.
I reblogged this on my blog. Thank you for this great information! We planted a lot of legumes for the nitrogen fixing properties but I am so happy to get some easy to read information about how it all works.
Thanks for reblogging! Yeah it’s fascinating although once you get into the whole nitrogen cycle it gets very complex all of a sudden and it’s all the more surprising that it just all ends up working… nature is ingenious!
I recently read an article (“Our Fertilized World”) in the May issue of National Geographic on agriculture via commercial (nitrogen) fertilizer and some case studies comparing Africa v China. I’m sure you’ve come across the majority points on the nitrogen fertilizer issue but it was still an interesting read! Thought I would pass it on!
Ooh, thanks for mentioning it, I’ll see whether I can find it somewhere!
This is a great post Janina. Except I disagree with your last sentence. I don’t think the process (fixing organic nitrogen through crop rotations etc.) ‘has been shown’ to be equally profitable’. Mainly I just object to using the phrase ‘equally profitable’ because I think it’s a bit misleading.
🙂