 But from the 1930s through the 1970s soybean acreage surpassed corn.Early in the 1970s grain and soybean prices, which had been relatively stable, "soared to levels that were unimaginable at the time".There were a number of factors affecting prices including the "surge in crude oil prices caused by the Arab Oil Embargo in October 1973 (US inflation reached 11% in 1975)".