Final answer:
The statement about increased soil erosion on US croplands since 1982 is false. Historical farming practices have degraded soil health, and the sustainability of croplands continues to be a concern due to past and modern agricultural methods.
Step-by-step explanation:
The statement that since 1982, the soil erosion rate by water on US croplands has increased is false. Over the years, especially in the 20th century, various farming practices have led to a substantial increase in soil erosion globally. Intensive cultivation has reduced soil's organic matter content, which can lead to floods, erosion, pollution, and further loss of organic matter. Historical data from the late 19th and early 20th centuries highlight the challenges faced by sharecroppers in the south of the USA, who used methods that increased short-term yields but led to long-term soil degradation. Some of these practices included overplanting and a lack of proper cover crops, which, together with natural weather events like rain and wind, exacerbated the problem of soil erosion. In addition, the significant expansion of agricultural production since the 1960s, which includes the use of modern farming methods and chemicals, has shown a mixed impact on soil health and has raised concerns about the long-term sustainability of croplands.