- Grass is a kind of plant
- In the erosion process roots of plants are an inhibitor
- The grasses are removed from the land
- So, the inhibitor of the erosion process is removed

- The inhibitor of the erosion process is removed
- The grasses are removed from the land
- Removing an inhibitor of a process causes that process
- Therefore, removal of grasses from the land will cause erosion

- Wind and rain cause erosion
- Soil erosion is when wind and moving water moves soil from fields / environments
- Hence, wind and rain can cause soil erosion

- Removal of grasses from the land will cause erosion
- Wind and rain can cause soil erosion
- So, removal of grasses from the land will cause wind and rain to erode the soil

Hence, removal of grasses from the land will cause wind and rain to erode the soil
Question: The prairie grass ecosystem once had a deep layer of topsoil which was protected by the grasses that covered it. Removal of these grasses for farmland is causing the soil to be eroded mainly by
Context: - Wind and rain cause erosion 
- Grass is a kind of plant 
- Soil erosion is when wind and moving water moves soil from fields / environments 
- In the erosion process roots of plants are an inhibitor 
- The grasses are removed from the land 
- Removing an inhibitor of a process causes that process