I don't know what version of TurboTax you are using to guide you there but you report installment sales in the Personal Income section, scroll all the way down to the bottom and find Less Common Income, look for Installment Sales click Start or Update for the interview. Farm land sales capital gain/loss will be reported on schedule D. Depending on how the sale is entered, gain/loss may be reported on form 4797 (Sales of Business Property) but will flow to schedule D.
