(2) If the economically feasible maximum corn stover collection radius is 20 miles, what is the minimum participation rate (%) of the farms to grow corn to produce sufficient corn stover to meet the feedstock need? The corn stover yield is approximately 3 metric ton/ac (dry). (Data: density of ethanol 0.789 kg/L; Conversion factors: 1 gallon = 3.785 L; 1 acre = 4,046 m2 or 0.0015625 mile2)