(a) The Federal rate may not exceed 80 percent.

(b) The maximum Federal rate (percentage) within each state for each practice or identifiable unit shall be established by the state conservationist.

(c) The maximum rate (percentage) for each county is established by the designated conservationist not to exceed the state rate (percentage).

(d) The rate (percentage) established by a state conservationist or a designated conservationist shall not exceed the amount necessary and appropriate to apply conservation treatment.