Like evasive chimpanzee said we need to poop INDIRECTLY in crops. Hot aerobic composting for example has excellent nutrient retention rates and eliminates nearly all human borne diseases. The main problem would be medication since some types tend to survive.

Also urine contains almost all of the water soluble nutrients that we expel and is sanitised with 6-12 months of anaerobic storage. So that’s potentially an easier solution if we can seclude the waste stream. Again the main issue would be medications.

I don’t have the answer, if it was easy we would have done it already. The main issue is we don’t have a lot of people working on the answer because we’re still in the stage of getting everyone in the world access to sanitation. Certainly the way we’re doing it is very energy and resources intensive, unsustainable in the living term, and incredibly damaging to the environment. We’ve broken a fundamental aspect of the nutrient cycle and we’re paying dearly for it.

The other problem is, like recycling, there isn’t a lot of money in the solution, so it’s hard to move forward in a capitalist system until shit really hits the fan.

1. We mine and manufacture nutrient dense fertilizer at massive environmental cost.
2. We use the nutrients to grow plants
3. We eat the nutrients in our food
4. We expel 95% of these nutrients in our waste
5. We dump our waste into the rivers and oceans with all the nutrients (often we purposefully destroy the nitrogen in the waste since it causes so much damage to rivers and oceans)
6. We need new nutrients to grow plants

Before humans there was a nutrient cycle. Now it’s just a pipe from mining to the ocean that passes through us. The ecological cost of this is immeasurable, but we don’t notice because fertilizer helps us feed starving people and waste management is important to avoid disease.

We need to close the loop again!