Answer:
Soybeans
Explanation:
Soy beans is an example of increased farming variety beginning in the 1970s. The 1970s period has been characterized broadly as a period of great farm prosperity, this is likely caused by a short period of high farm income.
In the early 1970s, soybean sales grew more than corn, this caused it to become America's number one cash crop.
They came from Europe because America had a booming economy.
A inflation rates of all north and South America
