I posted about the Tanbo Art back in 2005 - http://pacific-islander.
Tanbo Art has not been without controversy. In 2008, in an effort to cover costs, the village revitalization group who are responsible for the art, planted advertisements at the base of the pictures - one for Japan Airlines, another for a local newspaper. The town government was so angry that they threatened to no longer lease the land for the art in following years. After a vote by the townspeople, the rice seedlings for the advertising portions were removed.
This year, the Great East Japan Earthquake and Tsunami gave a new focus for the art and the messages grown in the rice.
The above picture is of Kaguya-hime, a princess from the Moon and the main character in Japan's oldest novel Taketori Monogatari, "The Bamboo Cutter's Daughter". She is shown being returned to the Moon at the end of the story. At the bottom is written : "Gambaru Japan!!" a common expression which has become the nation's post 3/11 slogan. It means "Do your best, Japan".
The second picture is of the Bamboo Cutter and his wife and the glowing section of bamboo in which, as the story goes, the princess arrived on Earth as a baby. Under it, it says "please think of others."
I also happened to write about the novel on my blog in 2007, as I have a beautifully illustrated and translated book of it. The original novel dates back to the late 9th or early 10th century. At the time I wrote that post, Japan had just launched a moon exploration probe named "Kaguya" after the Moon maiden.
That post is here - http://pacific-islander.
For more remarkable images of Tanbo Art, just search for it in Google Images.