After an order determining the amount of bonds which should be issued, the board shall call a bond election to submit to the voters a proposal of whether or not bonds in the amount determined in the order should be authorized when either:
(a) The board so determines.
(b) The board receives a petition requesting the election signed by either:
(1) A majority in number of the holders of title to land who are also the holders of title to a majority in value of all of the land.
(2) Five hundred or more persons, each of whom is either an elector or a holder of title to land and which petitioners include the holders of title to not less than 20 per cent in value of all of the land.
(Added by Stats. 1943, Ch. 372.)