In Baldo the Guardian Owls, you can collect items to aid you on your journey. One of these items is the shovel. To get the shovel you have to aid the Farmer and Mrs. Zirra.
To start the quest The Farmer and the Old Shovel you must first talk to the Farmer. He is working his field right next to where you wake up. If you talk to him, he will tell you that he has no use for the old shovel.
He will not give you the shovel right away. Instead, he will mention that Mrs. Zirra had some cabbages stolen and that she may need some help. Travel to the southeast and you will enter her farm. Once on her farm, you can turn right or left at the stream to get to her field. Talk to her and she will request your help.
To help her you will have to return to the Farmer as you need the shovel. The Farmer will then give you the shovel so that you can help Mrs. Zirra. Once you have the shovel you can dig in patches of dirt like the one the Farmer is standing in. Doing so unearths treasure and other items.
For more information on Baldo the Guardian Owls, check out How to get the Guardian's Horn in Baldo the Guardian Owls on Pro Game Guides.