@Article{essd-10-969-2018,
AUTHOR = {Cao, P. and Lu, C. and Yu, Z.},
TITLE = {Historical nitrogen fertilizer use in agricultural ecosystems of the contiguous United States during 1850--2015: application rate, timing, and fertilizer types},
JOURNAL = {Earth System Science Data},
VOLUME = {10},
YEAR = {2018},
NUMBER = {2},
PAGES = {969--984},
URL = {https://essd.copernicus.org/articles/10/969/2018/},
DOI = {10.5194/essd-10-969-2018}
}