Thomas Schendel

I think Anne Miller makes a very good point: The dynamic accumulator must be able to mine certain minerals/nutrients that are not easily available for other plants. Otherwise banans could be also considered dynamic accumulators, since they certainly take up a lot of nutrients - but the point is that these nutrients need to be bioavailable.

Since Coca can store many different nutrients it seems a good "pantry" plant to pick up from other composting plants, teas, fish emulsions, etc.

All this fertilizing methods you mentioned have one thing in common - their nutrients are highly bioavailable. It seems to be me that you are looking for a high recycling rate of organic mattter. In this case, instead of concentrationg on dynamic accumulators, I would recommend planting in different layers (strata) to increase biomass density per area. Combinations of banana and Chaya or egg plant and mung bean would be simple examples of planting in different strata.

Hello Susannah!

Unfortuantely I am not a good source of information for  your question, given that I have been never been to the Amazonas before. What comes to mind is cassava (they can extract Phosphor from the soil that is usually not available for plants) and bamboo (silicate). But well, that are rather generic examples.

A bit off-topic: You said you want to build soil. For my understanding, you can't build soil in the tropics (except with biochar --> terra preta). The high temperatures lead to fast decay, and the heavy rains lead to extreme leaching. The first time I tried to do compost in the tropics, I was left with a thin layer of organic stuff that didnt decompose (because it was too dry outside) and apart from that: there was really nothing left. Since then I learned to add soil and biochar to the compost (and turn it frequently).

You mentioned that there is mostly sand: - well, that is just another word for black hole, which sucks everything, nutrients, water, you name it. On the bright side, you will never understand these people talking about the problems associated with waterlogging

Rather than building soil, you can build soil life: beneficial bacteria and fungi, that help provide nutrients occurring in the soil that are normally not water-soluble and therefore not available for plants. I think that is what the rain forest is actually doing.

Tephrosia candida originates from the Indian subcontinent - so no worries here.

Acacia mangium can be considered invasive, but then again it is already grown commercially in the south of India - so its not that you are introducing something completely foreign. In my experience, Acacia mangium needs soil disturbance to successfully reproduce and cannot handle weed pressure well when very young. I wouldn't want to pass up the opportunity to work with this plant. Remember that this tree does not take heavy pruning well (but is fine with limited interventions that still yield substantial amount of biomass), so after a few years you are likely to phase them out and harvest the wood and biomass - which in turn also means that the number of flowering is rather limted.

Hey Kärlis, I have a very stupid answer to your question: It all depends on the specific conditions of your site! Annual rainfall, length of dry season, lowlands or elevated location, sandy soil or clay, acidic or alkaline soil, existing fertility...you get the idea. I would recommend that you study which plants actualy thrive near the location (e.g. what is growing at the roadside over there?).

So all my suggestions below may or may not work for you.

A)
-Acacia mangium. I observed that only the most shittiest conditions are barely good enough for this tree...even everything is dry as hell, but it keeps growing and growing.
-Leucaena (if the soil is not too acid); Since it may become invasive, you may not want to be the first person introducing it to the region. It is a common roadside weed, so you can find it easily if present.
-Neem tree

B)
-pigeon pea (drought resistant)
-Tephrosia candida (drought resistant)
-Bananas (only possivble if some fertilizer input is available); Their mulch is very helpful, because full of water.

C) Other stuff (yes, you didnt asked for it
-cow pea (annual)
-If you have grassland, you may just want to regularly cut it and organize the mulch in areas where you start growing stuff. The trick with tropical grasses is to cut them before they become monsters.

Of course, this is just a tiny fraction of possibilities, others will surely add more.

I have actually made the opposite experience: rubber trees really like pollarding! For background: My wife and I bought a former rubber tree plantation, where the rubber trees were felled prior to the land sale. However some of the trees came back to life. After a few years I cutsome of them at a height of ca. 1m. In most cases, the result was a vigorous regrowth. We also have a couple of smaller rubber trees in the roadside ditch, which are cut in a random way at least once per year - they all produce happy regrowth.

Our land has sandy soil and the rubber trees get maximal sunshine - maybe (or maybe not) this can explain our differing experiences.

I guess with strawberry guava you refer to Psidium cattleyanum und by "manage" you may refer to actions that stops this plant to take over the whole property (if I'm mistaken, you should ignore the rest of my reply ). On my land in Thailand (4 rai = 6400 sqm) this specie surely starts to outcompete other plants - its very shade tolerant, grows fast and tall, and the new shaded area of an established tree becomes the breeding ground for at least  another tree and bit by bit this plant conquers more area. Well, in my case (due to the small property size) I simply start cutting the trees. The foliage makes good mulch, and I use the wood for making biochar.

I have seen pictures that strawberry guava forms dense thickets, but this is not the case on my land - they grow as regular trees, which make it easier to deal with them.

Have you considered using sweet potatoes instead of potatoes?
At least they can make delicious french fries and are much better adapted to to the tropical climate.