Option 1: Deflation refers to the process by which wind removes and carries away loose sediment and soil particles. It does not cause soil erosion because it doesn`t involve the detachment and movement of soil particles caused by forces like water flow. Instead, deflation only transports already loose sediments.

Option 2: Deforestation can cause soil erosion as the absence of trees leads to increased runoff and reduced soil stabilization, making it easier for the soil to be washed away by water.

Option 3: Weathering refers to the breakdown of rocks and minerals into smaller particles by physical, chemical, and biological processes. While weathering does not directly cause soil erosion, it can contribute to the creation of loose particles that are susceptible to erosion.

Option 4: Overcropping, which refers to repeatedly planting crops on the same land without giving the soil adequate time to recover its nutrients, can lead to soil erosion. The overuse of soil depletes its organic matter, making it more vulnerable to erosion.

Therefore, the correct answer is Option 1.