Fertility Management for Coppiced Fodder Trees

I have roughly 1,000 landrace fodder trees in my back lot. Mostly Quaking Aspen with some cherry, elm, oak, beech and red maple. Once my hand heals I'll be planting 37 black mulberries and just bought cuttings of hybrid willow, hybrid poplar, and white mulberry to get rooted. I'm working the fruit trees and higher-growth hybrid trees in system with my pig pen to help feed the trees, basically just planting them outside the fence. Any tips for managing fertility for trees? Some of them will be harvested multiple times a year and some will be harvested every few years for useable firewood.

Hi Jordy,
I'm not a tree expert, but I think the two most common natural methods are to "chop and drop" and to use animals.

Chop and drop is where you grow things under the trees that will accumulate minerals or nitrogen, wait until they get big, and then you simply chop some or all of the plant and drop it in place. As they decompose the nutrients are made available to the tree.
With animals, you simply put a group of animals through the area at different times. Perhaps geese or sheep to keep the grass and weeds low a few times through the summer. Perhaps chickens in the fall to eat larva to reduce pest problems. Then while the animals are there getting a great meal... they leave behind some of their manure which also provides nutrients to the trees as it decomposes.

I like Matt's idea.

I would consider comfrey as a great chop-and-drop crop.  Comfrey also does OK but not great as it gets shaded out whereas some crops will simply die.  Also, maybe consider a nitrogen fixing crop to boost the growth of both the comfrey and the tree.

And while we are on this topic, maybe the best thing you can do is to manage erosion while hauling logs out.  Conveniently, trees are a sort of long-lived chop-and-drop plant in that they send down extremely deep roots.  Of course, getting nitrogen fixation is always a plus if you can manage it, thus the legume cover-crop plus comfrey.

I hope this helps,

Eric