Parts of Missouri are under extreme drought conditions. (See Missouri Agricultural Weather)

Here are some good information sources for dealing with problems caused by this year's drought

Nitrate & Prussic Acid Toxicity
http://muextension.missouri.edu/explore/agguides/crops/g04661.htm
List of Labs:
http://www.agebb.missouri.edu/haylst/t_labs.htm

Special Drought Issue of IPM newsletter
http://ipm.missouri.edu/ipcm/archives/v13n20/index.htm

MU Drought Info Page
http://agebb.missouri.edu/drought/index.htm