Row crop production occurs mostly in eastern Arkansas. During normal growing years, this region receives a large amount of precipitation, ranging from 46 inches per year in northeastern Arkansas to 52 inches per year in southeastern Arkansas (NOAA, 2009). However, most of this precipitation falls during the winter and early spring months. From late spring through early sum­mer most precipitation in eastern Arkansas falls as rain from widely scattered thunderstorms, which is often insufficient for crop production (Schrader 2010). Consequently, most eastern Arkansas row crop farmers depend heavily on irrigation water to grow their crops. Nearly 80% of Arkansas’ harvested cropland acres in 2011 were irrigated (Table 2). All rice acres and nearly all cotton acres were irrigated, while over three quarters of all soybean and corn acres were irrigated in 2011 (USDA, NASS, 2012a).

Most irrigation water is supplied by wells tapping into the Mississippi River Valley alluvial aquifer, which underlies nearly all of eastern Arkansas (Schrader 2010). Much more water needs to be applied during extremely dry growing seasons. This translates into higher pumping costs and reduced profit margins for producers. Groundwater is also an exhaustible resource in many parts of eastern Arkansas. Extensive pumping has caused a steady depletion of the alluvial aquifer in many areas of eastern Arkansas (Czarnecki 2010; Gillip and Czarnecki 2009; Schrader 2010), and several counties in eastern Arkansas have either partially or totally been designated as critical groundwater areas because of significant groundwater declines resulting from intensive irrigation (Czarnecki 2010; Gillip and Czarnecki 2009).

The two years of drought have also had a negative impact on production of the state’s most intensively irrigated crop: rice. Arkansas is the leading producer of rice in the United States, accounting for nearly 48% of U.S. rice production (Childs 2012). The rice crop suffered in 2010 and 2011 because of high night time temperatures associated with the drought. High night time temperatures negatively affect rice in two ways: 1) increased incidence of bacterial panicle blight; and 2) heat stressed rice kernels. Bacterial panicle blight is a disease that thrives during very hot years having high night time temperatures during July and August. Heat stressed kernels occur most frequently during growing seasons with high night time temperatures above 75 degrees Fahrenheit. Most commercial rice varieties grown in Arkansas are susceptible to high night time temperature, and both rice yields and quality were affected by high night time temperatures in 2010 and 2011.