The United States government generally tries to protect valuable natural resources.
Conclusion
One natural resource — topsoil — has been ignored for too long; federal expenditures for soil conservation are too low.
Evidence
Each bushel of corn might cost up to two bushels of topsoil. In many states topsoil has eroded from about 14 inches to 6–8 inches over 100 years. Despite this, federal soil-conservation expenditures are "ridiculously low" — in fact, total federal expenditures are less than the allocations of some individual states.
Evaluate
The question asks what the author does. The most concrete tactic in the passage is the comparison at the end: federal vs. state expenditures.
Goal
Find an answer that accurately describes a move the author actually makes — namely, comparing state to federal expenditures.