Agence France-Presse: Nicolas Denieul plants his spade in the ground and turns over a clod of soil to reveal a mass of earthworms seething around plant roots fat ones and thin ones, delicate translucent violet and dark brown. "That is magnificent. Ten years ago, I never thought I'd see anything like that!" said Denieul, a cheerful French farmer, his hands full of earth in the biting wind. For 10 years ago, there were no worms roaming about his land, near the western city of Le Mans, where he grows wheat, corn and...