Farmers and gardeners are used to feeding their plants with some type of food which could either be compost or fertilizers that are added to their water to help them grow so we could get a bountiful harvest. This is because all soils are not the same, as a lot of soil lack the nutrient required by plants to grow consistently.
It isn't like we started to practice the act of fertilizing today, we have relied on this practice for thousands of years and they help us to grow plants with high yields in whatever land is available and with synthetic fertilizers, growing high yield crop has never been easier and about half of the world depend on fertilizers to be able to grow the food they eat but there are a lot of things that go wrong just for food to get to our table using synthetic fertilizers.
The first of is the energy used to make them which comes primarily from fossil fuel and with the amount of energy used to make them, relying on them isn't a sustainable way to go in the future. Although there are other downsides to synthetic fertilizers like runoff but let's first discuss the energy problem first.
Scientists are looking into ways they can move out of fossil fuel dependence while keeping crop yield high and reducing greenhouse emissions. To do so, these researchers are looking to cut out the dependence on fossil fuel completely and to do so, they are looking to genetically engineer plants or microbes in plant to make their own fertilizer.
Plants require a number of nutrient to grow but they need three major ones which are Nitrogen, Phosphorus, and Potassium (NPK) with nitrogen being the most important nutrient on the list. Nitrogen is important in making chlorophyll which is important for plant survival, it i also important in making Amino acids which are protein building blocks. We have a lot of Nitrogen in our atmosphere but it isn't useful for majority of plants because they are in gaseous state so we need to help them get this nitrogen and this is where fertilizers come in.
Fertilizers can either come from natural process or synthetic with farmers using natural forms about 8000 years ago. Less synthetic fertilizer is required but people usually over apply them and the ones not taken up by the plant is washed out of the soil into water bodies. So while its use is adding to climate change, its production is a major factor in climate change and this is because the production is fertilizer is done using the Haber-Bosch process where hydrogen and nitrogen is combined at high pressure and temperature into ammonia which is then processed to become ammonium nitrate. The energy used in making this comes from fossil fuel and even with the increase in the use of renewable energy, it will be expensive to make the fertilizers with renewable energy.
In other to be able to get plants to get their own nutrient, the plant or the microbes in the plant root are modified to get nitrogen from the air and fix it themselves. Scientists are modifying nitrogen fixers and other microbes so they can be able to fix nitrogen. Scientists have been able to modify E.coli so it can be able to convert nitrogen gas into ammonia and to do so, they allowed the e.coli to possess nitrogenase genes but then the E.coli couldn't convert enough nitrogen for itself let alone the plant.
Researchers are further looking to engineer plant cells to produce nitrogenase thereby allowing plants to turn nitrogen gas into ammonia by itself but there are still certain setbacks which is still the energy talk. For that purpose, scientists are looking at the mitochondria to produce the enzyme since it requires a lot of energy but since nitrogenase can be turned off by oxygen, the mitochondria isn't seen as a great place since it requires oxygen to make ATP so researchers are looking into the chloroplast to help plant fix nitrogen by themselves.
There are lots of trials to help plant get the job done so we can reduce the effect of synthetic fertilizers on the environment but for now, they are all still work in progress and hopefully, we get one with the right solution soon so we can feed ourselves, save ourselves from runoffs, reduce energy consumption and reduce climate change.
https://cbmjournal.biomedcentral.com/articles/10.1186/s13021-019-0133-9
https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2018.00313/full
https://pmc.ncbi.nlm.nih.gov/articles/PMC5854654/
https://www.nature.com/scitable/knowledge/library/biological-nitrogen-fixation-23570419/
https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-019-0710-0
https://www.pnas.org/doi/full/10.1073/pnas.1305918110
https://ammoniaenergy.org/articles/industry-report-sees-multi-billion-ton-market-for-green-ammonia/
https://www.science.org/doi/10.1126/science.1254234
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0160951
https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.01794/full
https://pmc.ncbi.nlm.nih.gov/articles/PMC5334340/
It is clear that whilst fertilizer has its good of which feeding us is the greatest of all, it is affecting a lot of things including our ecosystem. For the fact that we use fossil fuel to make fertilizers, its just humans being humans. We create a problem and start to look for solutions to the problems that we created.