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Comment by scns | Hacker News Reader

Without excrement from animals you need synthetic fertilizer, whose production causes massive production causes massive environmental damage eg emissions and algae bloom.

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There's also the "classic" option, discovered some 200 years before synthetic fertilizers - crop rotation that includes some form of legumes. IMO with the current state of agriculture and food production we went into a local maximum that is very unsustainable and bad for the environment.

There's a reason we had to switch away from that. The crop rotation cycle isn't an efficient use of land. Synthetic fertilizers exist for a reason -- the human race wants and needs an excess of food. No one wants to switch to a model of food scarcity.

The point is that if the food is not meat we need like up to 75% less crops, which is completely attainable without synthetic fertilizer.

Claiming it does not make it so.

Every addition of a new consumer in a food chain brings with it a high rate of energy loss. The cow will need to use its energy to live, only a small portion of the energy is left in the steak you eat. 75% is a good approximation.

In general, the shorter the food chain, the more efficient it is. This is a universally known fact. I will drop some helpful links for you if you doubt this:

https://en.wikipedia.org/wiki/Energy_flow_(ecology) https://www.bbc.co.uk/bitesize/guides/z2m39j6/revision/6 https://scienceaid.net/biology/ecology/food.html#ecological_...

Source: https://ourworldindata.org/land-use

The figure given is 77% of agricultural land is used for livestock

That land use figure includes grazing areas, not just crop fields.

citation needed.

This is an all too easy narrative. Synthetic fertilisers might simply have caused an arms race for short term, higher efficiency which destroyed less efficient production techniques.

That does not make it long term efficient, see research on sustainable farming[0].

[0] https://rodaleinstitute.org/wp-content/uploads/RI-FST-Brochu...

Please define "efficient". Most arguments I've seen against crop rotation hinge on manual labour-type efficiency, not land yield-type efficiency.

That doesn't provide the same value as manure. Don't get me wrong, crop rotation is important because it provides different things.

Absolutely true. We can definitely be treating the land better.

The only reason we need industrial fertilisers, is because its packaged so well and easy to distribute. But if we weren't raping the soil in the first place, we wouldn't have this problem.

Industrialized farming needs to be revolutionised by the same technique that computing went through: a DIY revolution.

If you don't have a garden, now is the time to start. Everyone should have a garden.

A garden and a few chickens. Getting 4-6 eggs per day is simply fantastic, and the hens are great at eating up harmful insects and weeds that would otherwise harm the output of the garden. They also fertilize the land in a very natural way.

Manure and synthetic fertilizer both have similarly severe, but somewhat different, environmental impacts. Synthetic fertilizer requires large amounts of energy to produce, but manure generally needs to be applied much more inefficiently to achieve the same effect because of its relatively low nitrogen content and the inability to control its release. It also has transportation issues [1].

However, these types of impacts are trivial in comparison to the 1.9% energy efficiency for beef. Regardless of the fertilizer used, we would use just under 1/50th of it if we consumed the plants directly, along with the same savings in land and water.

[1] https://thebreakthrough.org/articles/to-cut-nitrogen-polluti...

But without animals you don't need nearly as much crops... Cattle do not come close to breaking even in this sense

Only a small amount of fertilizer usage in the US is waste based. In 2015 13M tons of nitrogen based synthetic fertilizer was used, on top of that 4M tons each of phosphate and potash fertilizer. For waste based fertilizer compost, dried manure and sewage total 600K tons. That doesn't even take into account that the raw weights aren't directly comparable.

https://www.ers.usda.gov/data-products/fertilizer-use-and-pr...

Last time I checked everybody I know is an fertilizer excreting animal..

it's because they're all made from meat.

http://www.eastoftheweb.com/short-stories/UBooks/TheyMade.sh... ?

yes, seemed to apply.

There is more than enough liquid manure, forcing farmers to pay for its removal (at least in Europe, that is). Also, it can be used only at certain points in time to avoid food poisoning.

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