Comment by teslabox | Hacker News Reader

Comment by teslabox | Hacker News Reader

There are options besides chemical fertilizers. The nodules on legume root are a symbiotic home for nitrogen-fixing bacteria. Farmers traditionally rotate corn and soybeans to reduce their nitrogen costs. Other plants have deeper roots, which pull up nutrients...

My comment about biological nitrogen fixation (15 days ago): https://news.ycombinator.com/item?id=29829580

Saw this recently: Black eyed peas could help eliminate need for fertilizer: Popular legume attracts beneficial nitrogen-fixing bacteria - https://news.ucr.edu/articles/2022/01/20/black-eyed-peas-cou...

One of the problems with holistic agriculture is you have to understand more about what plants actually need to grow, and think more to figure out how to work with what you've got. I used to have a local farm that made a great mulch with wood chips and feathers from their turkey operation. Blood meal [1] (nitrogen) and bone meal [2] (calcium, phosphorous) are also good fertilizers.

[1] https://en.wikipedia.org/wiki/Blood_meal [2] https://en.wikipedia.org/wiki/Bone_meal

That vastly underestimates the size of the modern problem. I posted previously of the adage "Modern agriculture is about turning energy in fossil fuels into food we can eat." While not entirely accurate (yes, most of the energy in plants comes from the sun, but it is fossil fuels that power most of the nitrogen fixation needed to unlock that photosynthesis), it does emphasize how so much of modern agriculture is dependent on extractive mining.

Saying "modern agriculture can switch to just planting legumes for nitrogen fixation" is like saying "modern transportation can switch to just using solar power." Of course, modern transportation can switch to using solar power, but most people understand how it will be a gargantuan, multi-decade, multi-trillion dollar process. Switching modern agriculture off its dependence on fossil fuels will be in the same order-of-magnitude difficulty level.

They only use fossil fuels to make the hydrogen. Which can be made more efficiently with electricity. So it's not really a problem. We only do it now because the costs are hidden. The transition is almost entirely political in nature, since not using fossil fuels for this is the better option, and it's already started.

> They only use fossil fuels to make the hydrogen. Which can be made more efficiently with electricity.

Are we really in disagreement then? Where pray tell do you think electricity comes from? In the US, 60% comes from fossil fuels, about 20% from nuclear. Solar, wind, biomass and geothermal combined is < 12%

My point is that most folks understand that moving our electric infrastructure to renewables is an enormous, long term, extremely expensive undertaking. Whether the hydrogen used in nitrogen fixation comes from natural gas directly, or from electrolysis, it's at its core an energy problem, and transitioning our energy use needed for nitrogen fixation on a global scale is a lot more expensive/complicated than planting some alfalfa.

Well, similar to the "EVs just burn coal" thing, it seems likely that burning the gas to make electricity and then using that electricity to make hydrogen would be more efficient, so doing it that way would reduce demand, save money, and just generally be better than what we do now.

And then you've a) freed up lots of a storable fuel that you can use to supplement renewables if you really need it (and can be kept and used as a chemical feedstock otherwise), b) created a whole new market for responsively using all the cheap new renewables that we need to build.

So, yeah, I think we still disagree. Fossil fuels are not particularly necessary, useful or cheap, not for transport and not for fertilizer. They have some uses, but they generally get given way more credit than they deserve for political reasons. Generally the faster we replace them, the better off we will all be in many ways. It's "expensive" to do this in the same way that moving to socialized health is "expensive", it'll costs billions, but it'll also save billions, because the alternative costs even more.

> it seems likely that burning the gas to make electricity and then using that electricity to make hydrogen would be more efficient

I'm not sure why one would think that, the exact opposite is true. Going to electrolysis is only desirable if the energy source is a renewable.

This article has a very good overview of the challenges with moving ammonia production to sustainable energy sources:

https://www.frontiersin.org/articles/10.3389/fenrg.2021.5808...

"challenges" and yet it reports the results of multiple studies saying our current options for green hydrogen are better than what we do now with fossil fuels, on multiple metrics and overall.

And like the "EVs burn coal" analogy, I'm suggesting we shift to renewables as quickly as we can, and there's no need to wait for the grid to be 100% renewable before electrifying as much as we can.

The union of concerned scientists has a map that compares the efficiency of an EV to ICE. It's lower in fossil fuel powered areas, but It's better than ICE everywhere today, even if you ignore the future greening of the grid. If you include that it completely demolishes the alternative.

So your document appears to support my point, why do you think it doesn't?

> most of the energy in plants comes from the sun, but it is fossil fuels that power most of the nitrogen fixation needed to unlock that photosynthesis

Just to build on this, we expend (at least) 7.3 calories of energy to produce 1 calorie of food (https://sustainability.emory.edu/wp-content/uploads/2018/02/...).

>There are options besides chemical fertilizers.

But as it relates to this problem (ie. food getting more expensive), your suggestion doesn't make any sense. Considering that the methods you described aren't widely used, I think it's safe to say that they're more expensive than using synthetic fertilizers. Therefore if we implemented that suggestion we wouldn't have higher food prices... because the food prices would be high to start with, probably much higher than it ever be with synthetic fertilizers.

We would also need more land to rotate and water. We are running out of both. Esp in the developing world the article speaks about..

There are techniques to cut down water consumption by quite a lot. As for the land; we'll have to invest quite a bit more in ecosystem restoration in the future.

Can we start now

In the US, perhaps we could stop the obscene subsidies for petroleum, corn, and meat, and subsidize more sustainable, nutritious and humane crops and farming practices.

If those existed and were cheaper, that would be done

If what existed? sustainable, nutritious and humane crops and farming practices? they do exist.

The person you're responding to said "existed and were cheaper," but you seem to have ignored the second conjunct of their claim in your response.

To be fair, that poster injected “and were cheaper” in response to a suggestion that subsidies should be moved away from substitutes and toward these practices, which probably wasn’t done in bad faith, but doesn’t exactly rebut the suggestion that subsidies would need to change to make this economically sustainable.

That presumes that those subsidies are for solely practical reasons, when in reality they're at least partially a political tool.

Of course they're not cheaper - they're not subsidized.

A no till rotational cover crop system with grazing is better in pretty much every way than monocropping with fertilizer, with the main downside being required knowledge of animal husbandry, along with some additional expenses in terms of fencing and some time investment in care of the animals.

From what I've read, the Haber process sustains well over half of the earth's animal population. Legumes can't provide enough nitrogen to maintain current levels of crop yields. Something has to give.

Too lazy to look up numbers, but in the US corn is a significant crop and much of it is more of an industrial feedstock rather than food for people.

I'm guessing that "more natural" processes could still feed us all but the game is rigged so that it's not economical for to do that (directly, as it's effectively subsidized for the "economical" side).

My readings were more ominous, that without the Haber process, more natural processes cannot extract enough nitrogen to feed us. That situation is partially alleviated if we stop eating meat, but not completely.

This is just one example of a larger realization, which is that humanity can no longer sustain itself without a complex and sophisticated technological society.

Good thing we are making that as fragile as possible by distributing resource extraction and processing 5,000 miles from where it ends up, with virtually no warehousing to absorb disruptions.

Corn is a very good carbon sink.

https://www.sciencedirect.com/science/article/pii/S016719871...

https://denvergazette.com/news/environment/one-global-warmin...

Carbon isn't nitrogen. The nitrogen needed for agriculture comes from the Haber process. What I'm saying is we can't just give up on the Haber process and go back to "natural" farming without figuring out how we're going to feed everybody.

... if it were used as a carbon sink.

But that cellulose "waste" part of the corn is a feedstock for other industries. Keeping those inputs constant means growing more of some other crop and increasing net nitrogen usage. Producing nitrogen fertilizer takes energy, currently from fossil fuels.

How readily would this be deployed to coffee farms in Brazil, staple foods in sub-Saharan Africa, watermelon farms in Colombia, coconut groves in Sumatra, palm oil in Malaysia, and rice paddies in the Ivory Coast? (All examples from the article.)

Poorly, but why keep at the Haber process for another century of historic growth and record mouths fed when we can instead try our luck with legumes?

Crop rotation, livestock integration and guild planting can be applied in all of those cases.

Crop rotation? Of perennials?

We could all benefit from eating more legumes in our diets, well most of us at least

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