In recent years, Iowa farmers have faced large variations in grain prices in short periods of time. Price variability stems from increased dependence on foreign markets and a wide range of world developments that affect cash grain prices. As an example of the potential impact on farmers, the variability • \u27 t \u27 ^ in 1980-crop prices during the last half of 1979 created a potential variation of $20,000 in net income from a 300 acre Central Iowa cash grain farm — depend ing on whether crops were sold at the high or low end of the range of available prices..