Half-century history of crop nitrogen budget and nitrogen use efficiency in the conterminous United States: Variations over time, space and crop types

Lu, Chaoqun

Half-century history of crop nitrogen budget and nitrogen use efficiency in the conterminous United States: Variations over time, space and crop types

Chaoqun Lu¹, Jien Zhang², Peiyu Cao¹ and Jerry Hatfield³, (1)Iowa State University, Ames, IA, United States, (2)Iowa State University, Ecology, Evolution, and Organismal Biology, Ames, IA, United States, (3)USDA-ARS, National Laboratory for Agriculture and the Environment, Ames, IA, United States