I-Team Investigates the cost of marijuana searches

Ohio's Marijuana Eradication Program removed 20,747 pot plants from farm fields this year. It was down from a record high of 84,660 in 2010.

The drop is attributed to a combination of increased enforcement and the movement of some grow operations indoors.

Scott Duff, Ohio Bureau of Criminal Investigation Special Agent Supervisor, said their efforts are having an impact.

"Now it is in small patches spread out," Duff said.

As Duff spoke, sheriff deputies and BCI agents moved through a corn field northwest of Greenville.

The contrast between the brown corn stalks and the bright green marijuana plants made detection easy from above. A helicopter carrying a BCI agent hovered over the field, allowing the agent to direct deputies to the pot plants.

The statewide cost for the program amounts to $500,000 a year. Most of that goes to pay for the helicopter and pilot. The money came from a federal grant through the Drug Enforcement Administration. DEA figures show there were only 27 arrests statewide last year. Authorities said it was nearly impossible to identify who planted the pot.

Shelby County had the most plants removed this year in the Miami Valley, with 493. Meigs County in southeastern Ohio had the most statewide, with 1,642.

Backers of legalized marijuana call the eradication program a waste of time and money.

Tonya Davis, of the National Organization for the Reform of Marijuana Laws Women's Alliance, said law enforcement would be better off focusing on heroin and prescription drug abuse.