You're absolutely right. I've even heard senior permaculture types suggest superphosphate for use as a one-hit kick-starter .. but as I say, Hügelkultur is not a particularly well proven method, and I suspect its primary benefits are enjoyed in an area with regular & frequent rainfalls.
For bang-for-back (or bang per kilogram, as transport may be the biggest expense in these environments) something like biochar would be a good import.
Guaranteed pest-free, lightweight, hard to make on-site, etc. Nutrient loss won't be as severe as in a heavy rainfall environment, but what little there is here you'd want to lock up before the next big rains.
For bang-for-back (or bang per kilogram, as transport may be the biggest expense in these environments) something like biochar would be a good import. Guaranteed pest-free, lightweight, hard to make on-site, etc. Nutrient loss won't be as severe as in a heavy rainfall environment, but what little there is here you'd want to lock up before the next big rains.