The drought that hit many parts of the Midwest during the spring and summer growing months is expanding.  Iowa Secretary of Agriculture Mike Naig says the drought monitor is now covering all parts of the Hawkeye state.  The extreme dry conditions are also affecting the barge traffic on the Mississippi River as the river depth is at its lowest level for several years.  Naig says agriculture could see a logistic nightmare with the low levels on the rivers, and the possibility for a rail strike to occur.  Naig says the potential rail strike will only compound the problems of transporting agricultural goods and commodities.