What factor most likely caused a decline in grange membership?

The price of wheat has crashed to the lowest level in a decade as huge harvests pile up in big growers from Russia to the US, cutting the cost of staple foods around the world. the major factor for the decline in grange membership is the wheat prices declined

S^2 = a4^2 = a4 * 4 = a16 centimeters = area of the square