We had outstanding success by planting a banana over a downed calf. A dozen
or so cats would probably work well too. As Doreen mentioned, it is organic
matter that counts. I trim all yellow leaves and use them, plus expended
"trunks", as mulch, over which I sprinkle spent chicken litter. The bananas
are mostly by the chicken coop and the chickens scratch litter out the door
almost to the base of the plants. I keep a circular fence around the bananas
to minimize attackes on the pups (chickens eat almost any green leaf) and
contain the mulch deeper than the chickens would otherwise allow.