In the practice of silvopasture, you have three simultaneous crops: the tree crop, the forage crop, and the livestock crop. As with other agroforestry practices, if you plan to use biocides (pesticides, fungicides, insecticides) and/or chemical fertilizers, you must be sure that all of the component parts of the proposed system can tolerate the additives. Foresters have a long-standing attitude that cattle and trees do not mix (because of soil compaction and rubbing around and on the trees by the livestock), but in this case, you are intentionally putting them together, ideally for mutual benefit.