Dave Bonta's speaker is simply delighted by the act of digging. The poem begins with a funny observation: a shovel looks like a spoon, and the soil seems like food, "heavy, brown" and full of odd objects like a stew. From there, the speaker walks through the job step by step, and nearly every stanza starts or turns on "I love" or "I even like."
The shovel is treated almost like a living thing. It is a tongue and a tooth, and a dance partner held out with brief solemnity before the "absurd little hop" onto the blade. Even the frustrating parts, like hitting rock or working around a stubborn root, become pleasures, especially the moment the obstacle finally lets go.
The mood is warm, playful, and a little affectionate. The ending lifts that mood further. The shovel holds its "unlikely prize," a stone or root perhaps, which the speaker calls "a tool nobody's invented a use for yet," suggesting that the odd things the earth gives up are full of possibility.