What do you think? My guess is that the wood will soak up the nutrients and release them to the hugel's biological community over time.

Ideally it could be pre-soaked. I fear that if the urine is applied when the wood is already mounded, a significant portion will fall through to the soil beneath.

This is a case where it's better to be whizzed ON, than whizzed OFF?

I whiz on the compost pile all the time, esp when I'm just starting one. Part of the benefits of rural living, I guess.

i collect p in an old milk jug then feed it to my veggies. i mix it with water before pouring on plants. they love it. the urine has actually brought a couple plants back to life. i was surprised that it had such a great effect. now i never flush my toilet and i have free fertilizer. pretty crazy that sewers were ever invented.

i personally dont think it will release slowly over time. i think you would have better luck just adding urine to your hugel once a week or every couple weeks after your garden has been established. just a personal opinion. i really have no idea. but that is what i will be doing after building my hugel.