A Missouri farmer who played a role in the largest organic grain fraud scheme in U.S. history has been sentenced to nearly two years in federal prison.

John Burton became the 5th farmer to receive prison time in the "Field of Schemes" case on Monday when he was sentenced by a federal judge in Cedar Rapids to 22 months behind bars.

Prosecutors said that Burton grew grain that he knew was not organic and sold it to Missouri farmer Randy Constant, knowing that Constant was going to market and sell it as organic.

Burton also worked for Constant, often spraying his fields with chemicals and fertilizers that are not allowed to be used on organic fields.

Constant is considered the mastermind of the $142 million fraud scheme, which tainted countless products that were marketed as organic. He died by suicide in August, weeks before he was to report to prison to begin serving a 10-year term.

Three Nebraska farmers have also received prison sentences in the case.