Tomorrow night will see the usual array of Independence Day fireworks displays across the U.S. (except where they are cancelled due to heat, extreme dryness and fire risks), but grain and soy markets have already been setting off fireworks of their own. At the risk of becoming overly dramatic, we might say that current grain and soy markets and the wildfires raging in Colorado, Idaho, Montana and South Dakota are symbols of what is happening to crops throughout much of the Midwest. Timber is burning and crops are firing under blazing heat, moisture sucking winds and very limited rainfall.There is no doubt that U.S. corn and soybean yields are in increasingly rapid retreat. USDA's weekly crop condition reports are mostly based on visual ob...