2024 Grow Food/Garden for Free Challenge

From what I've read, the advice is to store urine for at least a month so the pH increases and kills off any bacteria. The issue with that, in my experience, is when urine is stored for a long time, it starts to really pong. Also, some of the nutrients precipitate out of the urine as crystals of struvite, which can still be used as fertiliser but will clog watering can roses. Then there's the potential for introducing a lot of sodium in to the soil if the urine is from people with a high salt diet. My preference is to dump fresh urine onto the compost pile.

It is incredible how much nitrogen we flush down the toilet, 2-4 kg per person per year, apparently, so the same amount of N you'd get from 40-80kg of blood/fish/bone (which is mostly sand, anyway).