Soil Surface Roughness  

Soil surfaces that are smooth offer little resistance to the wind. Keeping the surface rough by tilling when the soil is moist enough to form large clods will reduce wind erosion. Although, it is important to recognize that excessive and frequent tillage can gradually reduce roughness of soil by breaking clods and aggregates that resist erosion. Tilling a dry soil may cause a dry dust to form, which aggravates the erosion problem.

Unsheltered Distance  

The lack of windbreaks allows the wind to put soil particles into motion over greater distances thus increasing the abrasion and soil erosion. There is no obstacle to reduce wind velocity.

Wind Velocity and Turbulence  

Wind erosion potential begins when the wind speed increases to 25 km/h (15 mph). Soil movement increases by the cube of the wind velocity, so the amount of soil transported increases rapidly with wind speed. Turbulent winds carry soil particles into the atmosphere to greater altitude, and increases soil particle detachment.

Factors and processes of wind erosion are explained in this video clip. The clip explains how wind velocity or speed affects wind erosive energy. The video also explains how the nature of the soil surface affects erosive wind energy. Video Clip by Dr. John Tatarko, USDA