Rainforest trees grow bigger, faster

I think this will work with any crop, trees or not.
the pacific islanders have been putting small unedible fish that would normally be wasted under crops for eons.

below from csiro
http://www.csiro.gov.au/files/mediaRelease/mr1999/Rainforest.htm

Rainforest trees grow bigger, faster
Rainforest trees planted on farms in north Queensland can grow 50 percent bigger within three months of planting and use far less fertiliser, due to an innovative technique developed by CSIRO scientists.

The method is proving so successful it is already being exported to Australia's Pacific neighbours, Fiji, Samoa and the Solomon Islands.

The new technique uses slow release fertiliser within a nursery medium so that the fertilisers are already in the root zone of the nursery seedlings before they are planted.

This technique uses 30 times less nitrogen and 100 times less phosphorus than is currently used by industry on tree seedlings after they have been planted.