Garrulous and affable, Mr. Morales all but fizzes with energy and ideas. As he threaded his way through the streets of Harlem after visiting one of his compost sites one recent day, he pointed to a community garden: He’s aching to stage an intervention on its saggy looking compost bins and install a concrete pad that would deter rats and make shoveling easier. He also thinks the manual labor involved in composting could be packaged as outdoor workouts he’d call “Motion with Meaning,”…