Final answer:
The fields were only used for a few seasons due to various reasons such as short-sighted farming practices and the need for maximizing productivity. This led to the depletion of soil nutrients and erosion, rendering the fields less fertile over time.
Step-by-step explanation:
The fields were only used for a few seasons because of various reasons. In earlier agricultural societies, farmers depended on crop rotation to rebuild soils after periods of intensive planting. However, as farmers started earning money in the market by feeding urban industrial workers, some were unwilling to let a significant portion of their farms lie fallow each year. They preferred to amend their soils rather than waiting for fertility to regenerate naturally. This led to the depletion of soil nutrients, which made the fields less productive over time.
In some cases, farmers who didn't have access to enough manure to supplement their soil opted for an alternative method. Satellite photos from the 1970s showed that informed farmers who carefully rotated their grazing animals and allowed the fields to lie fallow periodically had healthier and fertile land. On the other hand, nomads who didn't plan for the impact of increasing their cattle on the greater good had bare and devastated land outside the fenced areas. This unsustainable practice caused erosion, depletion of vegetation, and ultimately, the death of both cattle and people.
In another example, the practice of overplanting and using fertilizers in the Deep South of the United States in the 1800s caused the degradation of land. Sharecroppers needed to maximize every acre of land to escape debt, so they used methods that increased short-term yields but depleted the topsoil. This unsustainable model destroyed the productivity of many Southern farms and led to soil erosion and the deposit of silt and fertilizer into Southern rivers.