Soil erosion has been happening since the Earth was formed, so it wasn't "discovered" in the sense of a single event. However, we can trace the understanding of its significance and its impact on human activities through history:

* Ancient Times: Farmers in ancient civilizations like Mesopotamia, Egypt, and China recognized soil erosion as a problem. They employed techniques like terracing and crop rotation to combat it.

* Early Scientific Observations: In the 17th century, scientists like Edmond Halley began to study soil erosion and its impact on landscapes.

* 19th Century: The Industrial Revolution led to more widespread deforestation and agricultural practices that intensified soil erosion. This prompted more scientific study and concern about the issue.

* 20th Century: The Dust Bowl in the 1930s was a stark reminder of the devastating consequences of soil erosion. This period saw a surge in scientific research and government programs focused on soil conservation.

* Present Day: Today, soil erosion remains a significant global issue. Scientists continue to study its causes and develop solutions to mitigate its impacts.

Therefore, while soil erosion has always existed, our understanding and awareness of its impact have evolved over time, spurred by historical events, scientific advancements, and growing concern for its consequences.