The first shelf is available right from the start. Seeds or decoration objects are automatically stored there.
Please note that decoration objects always occupy two shelf spaces.
If you complete quest number 18, you can buy a second shelf for 12,500 pD, and if you have a premium account, you can even buy a third shelf. These options are displayed in your farm house.
If there's no more space on your shelf before you can buy a second one, you can outsource your products via contract. In order to do this, simply send yourself a contract with the desired amount of products. Simply decline or cancel the contract in order to regain the merchandise. Make sure there's enough space on your shelf by then, or else this option is not displayed.
Should your premium account have expired, your premium shelf will be "frozen". The goods from this shelf will be transferred to your first shelf (as soon as there's enough space).
If you reactivate your premium account, your premium shelf will be "unfrozen".