The 35,000-acre campus of the Clay Center USMARC facility was established in 1964. (Courtesy of the University of Nebraska-Lincoln)LINCOLN — Some U.S. Department of Agriculture researchers could be relocated to Nebraska under a plan to close a Washington D.C.-area research facility. Nebraska researchers say more USDA personnel could benefit the state’s research efforts, but with few details shared about the project or staff movement, how much he…