I was given a gift of wheat that was given pretax. I then sold it. How do I manually report this on form 8949?

When you enter investment sales or exchanges from Form 1099-B or 1099-S in TurboTax, it'll automatically (no manual entry required) fill out Form 8949 and transfer the info to Schedule D. You don't need to fill out the 8949 form yourself. For more information see this TurboTax article.

To report the sale of gifted wheat in TurboTax, follow these steps:

Sign in to your TurboTax account: Be sure you log in before step 2.

Click on "Investment Income": Then select "Stocks, Mutual Funds, Bonds, Other."

Enter Sale Information: Enter a Description 

• What type of investment did you sell?: Select "Other."
• How did you receive this investment?: Select "I Received it as a Gift."
• Continue through the remaining questions

Review and Confirm: TurboTax will calculate the gain or loss and include it on Form 8949.