Deductions & credits

Make sure you are in the Personal tab of Home & Business (unless this is business-related land sale).

Under 'Personal Income' scroll down to 'Investment Income', and Start under 'Stocks, Bonds, ...'

Say Yes you sold an Investment, No you didn't receive a 1099-B.

You'll get a screen where you need to type 'Land' as description (screenshot). 

If the land sold is Business Property, under the 'Business' tab, scroll down to 'Less Common Business Situations' and Start at 'Sale of Business Property'.