Final answer:
Soybeans have become a key part of Argentina's economy due to their low need for fertilizer and wide range of uses. Crop rotation between corn and soybeans benefits soil health and pest management. Unlike corn and soybeans, wheat did not originate in the New World.
Step-by-step explanation:
The crop that has become a major part of Argentina's economy because it does not need much fertilizer and has a variety of uses is soybeans. Soybean cultivation offers significant economic advantages in Argentina, placing the country as a top global producer along with the United States and Brazil. Farmers often implement a practice known as crop rotation, where they alternate between planting corn (a cereal crop) and soybeans (a legume) in different seasons. This type of rotation can improve soil fertility and reduce the spread of pests and diseases. While corn is a staple crop worldwide and has a variety of uses including food products, fuel, and animal feed, it is soybeans that fit the specific criteria mentioned in the question.
It is noteworthy that among the crops listed (corn, soybeans, and wheat), wheat is the crop that did not originate in the New World. Tobacco, maize (corn), and potato are all crops that originated in the New World, contrasting with wheat, which has its origins in the Old World.