From ancient times a soldier taking part in a campaign was obliged to carry army provisions and, under Ritsuryo law, they had to pay his own expenses: about 108 liter of dried rice and about 3.6 liter of salt, however, these supply would last only 60 days and carrying a large amount of food could hinder a march.
古来から従軍する兵士には兵糧携帯の義務があり、律令法においては糒6斗及び塩2升の自弁が定められていたが、実際には60日分に過ぎず、かつ大量の兵糧携帯は場合によっては行軍の妨げになる可能性もあった。