Hacker News Reader

Comment by jackyinger | Hacker News Reader

This is very interesting from an agricultural perspective. According to the Wikipedia article for ammonia, “In the US as of 2019, approximately 88% of ammonia was used as fertilizers”.

To me this is a very interesting and damning fact with regards to current dominant agricultural practices. Yet another reason that it would be beneficial to further redevelop closed loop nutrient systems. For instance, sewage solids from cites in are sold to farmers for use as fertilizer.

Funnily enough Fritz Haber (who developed the Haber Process used to manufacture ammonia) also developed chemical weapons in WWI. Some people claim he is somewhat redeemed by his contribution to artificial fertilizer. I disagree with this reasoning on several levels.

View on HN

> For instance, sewage solids from cites in are sold to farmers for use as fertilizer.

If this was human waste wouldn't it have to be treated to remove chemicals viruses? Couldn't you get HEP-A from this process? Seems impractical and dangerous.

Biosolid fertilizers are widely used for decades in turfgrass. That’s not a claim that they’re risk-free, but rather just noting that it’s a well-established process.

Milorganite is probably the best-known nationally available brand you can buy in the home center near you, but some municipal treatment plants also sell locally to small/home users in addition to the more commercial scale usage (golf courses, etc)

I’m not sure of their level of use in feed grasses.

> For instance, sewage solids from cites in are sold to farmers for use as fertilizer.

Seattle tried shipping their shit (literally) to the farmers in Central Washington. Used these trucks that had "loop: turn your dirt around" splashed on the side. Then the farmers decided maybe they ought to test that stuff for PFOA/PFAS before applying it to their most valuable asset.

You don't see those trucks anymore.

A local "green" grocery went from selling hot food in plastic clamshells to using compostable cardboard. One guess what that cardboard is coated with to prevent liquids from soaking into it.

Why is it damning that 88% of ammonia is used in fertilizer? Is their some other industry that ought to consume a larger percentage?

We could avoid this number by investing in soil preservation, nitrogen fixing plants, reduce meat consumption, even in concepts like humanure.

None of these would produce as much food per area and time. Reducing total calories required by eating less meat is a different argument.

Didn't said that we can substitute industrial ammonia but it could definitely reduce it's use. Changing the way we eat it's definitely an opportunity to reduce major sources of c02 emissions.

We abandoned "closed loop nutrient systems" long time ago for good reasons. Prion and hormonal pollution are comparable to radiation.

Also "Fritz" is very nacy name. And fertilisers can be used as bombs. Very very bad bad!

The story of Fritz Haber first wife is very sad https://en.wikipedia.org/wiki/Clara_Immerwahr

I wonder why you see his chemical weapons developments during WW1 as a particularly egregious sin.

My great grandfather was on the front lines in France and was gassed several times. To the day he died you could see the veins in his eyes from that experience, but when I went to the local VFW with him as a child and saw the men with no arms or no legs - the product of boring old TNT and shrapnel - I would always ask myself why we handwave that as the costs of war.

The energy use of agriculture is overstated. It's a rather minor part of the energy consumption of society overall. In the US we use more energy cooking food than we do growing it (which is about 1% of total energy use). (Note: this ignores the direct use of sunlight falling on fields growing crops.)

> For instance, sewage solids from cites in are sold to farmers for use as fertilizer.

That's how we get the next pandemic.

Reply on news.ycombinator.com