Iowa’s farm economy may be a bubble ready for bursting. Sale-barn managers say Iowa farmers are collecting record prices for their cattle these days. Last year farm income set a record in the midwest and prices are soaring even higher for beef, with plenty of corn at just two dollars a bushel. With Canada’s border closed to imports of cattle, the numbers of fed cattle going to market are limited, another thing keeping prices high. Auctioneers say that’ll change if a USDA order to re-open Canadian imports goes into effect, and warn that with the high price of cattle, farmers themselves could find it tough to afford feeder cattle to stock their lots later in the summer and fall.