• @[email protected]
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    38 months ago

    That alone is still not infinite. When you eat food you’re taking the nutrients that you need out of it and excreting what is left. So even if all of your shit went directly to manure then you’re still putting in less than you took out.

    • @[email protected]
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      98 months ago

      The energy input is the sun, and most of the calories come from the air (carbon dioxide). Given so much external input, harvesting from a plot without reducing soil fertility is totally possible. With nitrogen-fixing crops (soybeans being the poster child), even the nitrogen fertilizer comes from the air.

      • @[email protected]
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        48 months ago

        The plants use energy from the sun to turn carbon dioxide from the air into edible calories. When our animal bodies “burn” the food we eat, that turns it back to carbon dioxide, which we exhale.

      • @[email protected]
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        18 months ago

        That’s like counting tigers in the zoo as tigers in the wild. Dust from homes gets put in landfills, corpses get burnt or buried in boxes, human excrement gets treated and reintroduced to streams. It’s not finding its way back to the fields in such a way that it’s 100% efficient, not even close.

        • @[email protected]
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          28 months ago

          Not all the matter in farming fields come from fertilizer. A lot of it comes from CO2 in the air, which will eventually go into some plant that we can eat. Also, all those ways that matter is lost, therefore not being 100% efficient doesn’t make matter disappear. Burning turns it into CO2 -> it will reach a plant. Excrements going into water streams -> plants will pick them up, or ocean wildlife will pick them up. Buried corpses -> microbes and plants will pick them up. The only way to “lose” matter is for it to leave the atmosphere into space or to be buried so deep that no life can reach it.

          The atmosphere loses matter at a rate that is (presumably) not affected by human actions.

          Matter buried too deep is compensated by matter coming out from volcanic eruptions.

          As long as the earth’s core is hot enough for volcanic activity and the sun doesn’t run out of fuel, the cycle keeps going.