Columbia subject headings:
Agricultural conservation--Law and legislation--United States.
Agricultural ecology--Research--United States--Finance.
Agriculture--Research--Law and legislation--United States.
Carbon cycle (Biogeochemistry)--Research--United States--Finance.
Harvard subject headings:
Agricultural conservation--Law and legislation--United States.
Agricultural ecology--Research--United States--Finance.
Agriculture--Research--Law and legislation--United States.
Carbon cycle (Biogeochemistry)--Research--United States--Finance.
Princeton subject headings: