Check the addresses again. Compost is not mentioned anywhere else except motionpatheffects and compostEffects xmls
Also might have to have it in densityHeight.xml too if not already. Just check my map xmls, search for compost and see what you are missing, but I think is only an address problem.
If you use Precision Farming, you will have to have the script too, with the PrecisionFarming.xml (also check the xml address in the lua to match)