Lewis & Short

fēcundo, āre, v. a. [fecundus], to make fruitful, to fertilize (poet. and in post-class. prose): (Nilus) viridem Aegyptum nigrā fecundat arenā, Verg. G. 4, 293; Claud. I. Cons. Stil. 239; Pall. 3, 9 al.