Fact 1: Being exposed to wind can cause erosion of soil.

Fact 2: Soil erosion causes crop yields to decrease.

Given the two facts above, answer the question "What is a possible negative effect of exposing soil to wind " with the following options: 
- It used to be covered by water
 - exposure to cold
 - decrease in crop yields
 - greater food production
 - elimination of harmful pests
 - a tree falling
 - wind power increases
 - Damages them


 

   decrease in crop yields      