We had to go over the other side of Chatellerault the other day and wending our way back we encountered a number of pale lavender fields. So we stopped to take photos and I identified the crop as lupins. We've never seen lupins being grown here before. Most years I spot a number of fields of fava beans (field beans, broad beans) and last year for the first time I saw crops of peas and soy beans (Chris Luck had some interesting things to say about soy bean cultivation in France recently on his blog). Further east, around Issoudun, lentils are widely grown.
These lupins appear to be White Lupin Lupinus albus graecus, also known as Field Lupin. White lupins have a spring and a winter form so I imagine that explains
why they are flowering in April (ie they are the winter form, sown to
overwinter and flower in the spring, like canola). This isn't a traditional pulse in central France, but I've seen them for sale in the supermarket in the North African section. There is a significant Portuguese population in the area too, and they appreciate White Lupin, so I suspect this crop is for human consumption, not animal feed.
Lupins should thrive here because there is already a local species, Narrow-leaved Lupin Lupinus angustifolius, now very rare in the wild (its beautiful royal blue flowers can be seen on the roadside opposite the entrance to LeClerc at Ville aux Dames in the summer). Lupins like the sandy soil that occurs in pockets in the river valleys. Ironically, Narrow-leaved Lupin has been developed as a crop in Australia and 85% of the world's production of this species is in Western Australia.