Bertonico is a comune (municipality) in the Province of Lodi in the Italian region Lombardy, located about 45 kilometres (28 mi) southeast of Milan and about 15 kilometres (9 mi) southeast of Lodi.Bertonico borders the following municipalities: Ripalta Arpina, Moscazzano, Montodine, Turano Lodigiano, Castiglione d'Adda, Gombito, Terranova dei Passerini.Economy is mostly based on agriculture and animal husbandry.