Here is my first attempt at conveyor belts. The item router on the left will have a pipe feeding it fertilizer (not built yet). It will get split equally down the blue and green paths (right and left), then the next item router will take half and deposit it in the fertilizer, and send the rest out the back and on to the next fertilizer. Item routers will pull items off conveyors if it can be routed. The last router (far right under conveyor) will pull out the remaining fertilizer and deposit it in the machine below if there is space. If it is full, It will leave it on the conveyor and the item collector will deposit it in the chest. Eventually, the chest will be attached to the AE network, but I haven't gotten that far yet.
The fertilizer machines have a tin upgrade and can handle the 9x9 farm. The farms themselves will be golem powered. I figured this is a good way to use the extra fertilizer as with my sewer and composter running, I produce more than my tree farm needs.
I can't figure out a good way to do an even split with pipes, but with conveyor belts and item routers, it is easy.