I would mix in a little bit of 魔肥 with the soil as 基肥.
As I heard that 魔肥 is a slow release fertiliser which only releases as much as the plant requires, I think it should be pretty save for the AV. However, having said that, its better save than sorry, and I'd never put too much into the soil mix. My main source of fertilisers will be the water soluble type |