Agriculture, horticulture, nurseries, greenhouses, orchards and general farming, including raising and pasturing of livestock, goats, hogs, etc., but not dry-lot feeding and raising, fattening, killing or processing of chickens, turkeys and other poultry, providing there shall be no feeding or disposal of garbage, rubbish or offal unless a permit for such operation is issued by the Board of Aldermen under such restrictions as the Board of Aldermen may impose.