Production and application of manure nitrogen and phosphorus 1 in the United States since 1860 2 3

Production and application of manure nitrogen and phosphorus 1 in the United States since 1860 2 3 Zihao Bian, Hanqin Tian, Qichun Yang, Rongting Xu, Shufen Pan, Bowen Zhang 4 5 International Center for Climate and Global Change Research, School of Forestry and Wildlife 6 Sciences, Auburn University, Auburn, AL 36849, USA 7 Department of Infrastructure Engineering, The University of Melbourne, Parkville 3010, 8 Australia 9 Department of Environment, Geology, and Natural Resources, Ball State University, Muncie, IN 10 47306 USA 11 12 Correspondence to: Hanqin Tian (tianhan@auburn.edu) 13