> Ammonia (NH₃) is the foundation for the nitrogen (N) fertilizer industry. It can be directly applied to soil as a plant nutrient or converted into a variety of common N fertilizers
> Ammonia has the highest N content of any commercial fertilizer, making it a popular source of N despite the potential hazard it poses and the safety practices required to use it. For example, when NH₃ fertilizer is applied directly to soil, it’s in a pressurized liquid that will immediately become vapor if exposed to air after leaving the tank. To prevent such releases into the atmosphere, growers use various tractor-drawn knives and shanks to place it at least 10 to 20 cm (4 to 8 inches) below the soil surface. Ammonia will then rapidly react with soil water to form ammonium (NH₄⁺), which is retained on the soil cation exchange sites.
Yeah, ok, ammonia is not completely useless as a fertilizer. You can't do that process in any soil, and can't repeat it many times on the same place either. But it is used a few times in a few places.
(Interestingly, I live in a place that would gain a lot from it, yet people overwhelmingly prefer to use magnesium and calcium during the PH correction of the soil. Now I'm curious about the reason.)
There is also ammonium nitrate, that is a much safer and easier to handle carbon-free alternative to ammonium and much more widely applicable. It is still more dangerous and harder to handle than urea, and also requires equipment renovation (so, don't expect people to change any fast). But if the carbon becomes a hard constraint, people will very likely migrate to it or something similar. The problem we are seeing right now is that any migration takes time and money.
Yeah, it's one of the top 5. Notice there are no numbers there.
It's hard to find numbers, most places basically ignore the usage as a direct fertilizer. It seems to be much more popular on the US than anywhere else, for the US I was able to find this (it's old, but it's what I have):
> Urea is the most popular source of dry N fertilizer, accounting for 79% of the
total dry N used. Ammonium sulfate has risen in popularity. In 1988 it constituted 14% of the dry N market. (https://www.canr.msu.edu/field_crops/uploads/archive/E0896.p...)
Most countries just equate nitrogen fertilizer with urea.
> Ammonia (NH₃) is the foundation for the nitrogen (N) fertilizer industry. It can be directly applied to soil as a plant nutrient or converted into a variety of common N fertilizers
> Ammonia has the highest N content of any commercial fertilizer, making it a popular source of N despite the potential hazard it poses and the safety practices required to use it. For example, when NH₃ fertilizer is applied directly to soil, it’s in a pressurized liquid that will immediately become vapor if exposed to air after leaving the tank. To prevent such releases into the atmosphere, growers use various tractor-drawn knives and shanks to place it at least 10 to 20 cm (4 to 8 inches) below the soil surface. Ammonia will then rapidly react with soil water to form ammonium (NH₄⁺), which is retained on the soil cation exchange sites.
https://www.cropnutrition.com/resource-library/ammonia