Farming in Ibaraki

Apparently Ibaraki-ken is the second largest farming prefecture next to the island of Hokkaido. And what a lot of work it is. As a close look at the photos indicates some plants are protected by a pyramidal white enclosure barely covering the plant and a clear plastic one meter high greenhouse like structure covering the whole row. This greenhouse is partially covered with straw bundles. Later I found out that these plants are the famous Edosaki kabocha (pumpkin) which need to be ready for the consumer in June. Frequently a variety of plants or seeds are planted in holes in plastic stretched over the soil. This acts as a mulch and keeps the soil warm.
The field of purple flowers is the Japanese variation of creeping charlie and today April 2, 2012 these were simply being tilled into the soil. Two of us have spent many hours weeding and collecting this pest as can be seen in the pile in the one photo. Why farmers tolerate this weed and let it grow on the edges of the fields and presumably produce seeds as evidenced by the millions of baby creeping charlies? Is it because in Japanese it's name designates a sitting Buddha? As Kenji, a friend of Akio Okano, states one season of seeds is followed by ten years of weed growth. Organic gardening aside this noxious pest deserves a lot more killer instinct.
When the government today lowered the allowable radioactivity level from 500 to 100 becquerels, Japan will need all the production it can muster.