WICHITA (AP) - The U.S. Agriculture Department is estimating the total value of Kansas crop production last year at $7.79 billion, a drop of 4 percent from 2012. The agency's National Agricultural Statistics Service calculates crop values by multiplying the average marketing price by the amount of production in each state. Friday's report said Kansas wheat production in 2013 was valued at $2.22 billion, down 22 percent from the previous year. The value of Kansas corn produced for grain was pegged at $2.31 billion last year, a drop of 13 percent. Soybean values for 2013 were estimated at $1.59 billion, up 30 percent from the previous year.