Answer:
A common export for 1500's America was fruit.
The candidate had to be trained as a scholar and then pass a series of written examinations. The Chinese civil service system, established in 124 B.C.E., required potential officials to be trained as scholars and then pass rigorous examinations to qualify for office.
One reason: Plowing large areas of land
A few more reasons: poor farming practices, farmers would loosen up the soil, and the land was deforested, making it loose the roots that held the soil in place.