Lewis & Short

laetĭfĭco, āvi, ātum, 1, v. a. [laetificus],

  1. I. to cheer, gladden, delight; constr. with abl. (rare but class.): non illum gloria pulsi Laetificat Magni, Luc. 3, 48: sol laetificat terram, Cic. N. D. 2, 40, 102; Vulg. Psa. 21, 7: corda, id. ib. 19, 9; 103, 15.
    Mid., to rejoice, be glad respecting any thing: nunc eo alii laetificantur Meo malo et damno, Plaut. Aul. 4, 9, 15.
  2. II. In partic., in agriculture, to render fruitful, to fertilize, enrich, manure the ground: Indus agros laetificat et mitigat, Cic. N. D. 2, 52, 130: faba solum laetificat, Plin. 18, 12, 30, § 120: agrum, id. 17, 9, 6, § 50: laetificata seges, Sedul. 1, 41.
    Hence, laetĭfĭcans, antis, P. a., rejoicing, joyous (ante-class.): unde ego omnes hilares, lubentes, laetificantes faciam ut fiant, Plaut. Pers. 5, 1, 8.