Many exotic plantations are being promoted in wet lands particularly close to paddy-rice agroecosystems. It will be interesting to know the possible impact of popyphenols on the morphology, physiology, energy partitioning and molecular level.
Several agroforestry solution were tested in rice asfor Vetiver-rice combination. This is supported by FAO ICRAF in the philippines. As far testing biocompatible solutions you may try to use pot trials with and without active charcoal up to 6% in volume. This agent will remove root exidates and if the soil was taken under the trees you like to test, the rice seedling growth rate will be higher in amended soil.