I wrote many poems on this single day. Sometimes I guess the inspiration builds up like in a dam only to burst out when one turns the tap.
I like this haiku myself as I find it subtly witty through the connection between nature and man made things; also acknowledging the farmer as an artist. The poem also has a human touch like haiku are supposed to have. The seal I'm talking about is the red and white seals used for signing. Here more in the sense of a white-characters-on-a-red-background (inkoku) version of an artist's seal (rakkanin) on the finished piece of art. For an example, just take a look at my deviantART icon:
Hope you enjoy