In natural tropical environments the nutrients aren't in the soil, they are almost all tied up in the living biomass, and as soon as some of that dies the nutrients it releases are absorbed by other living vegetation. And generally, if we want to do things in a way that's sustainable, we should look to nature and try to imitate it (and once we can manage that, try to improve on it).
What I've found is that the only way of doing tropical agriculture that's remotely sustainable is "slash and drop" agroforestry, which is where you interplant (a lot of) biomass for mulching together with your crop plants and keep cutting/pruning that to produce mulch, so that you can keep your crop plants heavily mulched all the time. This is fairly labor intensive, though, and worse, it requires highly knowledgeable labor to maintain.