Weather and production agriculture are inseparable. In the past, the weather market season nominally lasted until about 15 December. With the emergence of South America as an important producer and exporter of soybeans and corn, however, it never ends.In yesterday's WPI report, Dave Juday commented about the impact that severe winter weather has had on energy markets and even the first quarter U.S. gross domestic product (GDP) during 2014 and again this year. Weather is something we accept and live with every day. Those of us involved in agriculture ought to have an elevated sensitivity to it, but sometimes we can still forget just how pervasive the impact of weather, bad or good, can be.Weather and production agriculture are inseparable. B...