This is the waste that is left over from processing salad greens. These greens are very edible. The stems may be a bit too twiggy for a raw salad, but they would work well steamed a bit. They’d also be good for soup or to make broth. The chickens will eat them. Tossed into a compost pile, all sorts of organisms will convert it into rich compost. Then it will grow more wonderful salad greens.
There really is no such thing as waste on a produce farm. Everything is part of a continuous process, going from one state to another.