sustainability Article Effects of Different Fertilization Regimes on Crop Yield and Soil Water Use Efficiency of Millet and Soybean Qiang Liu 1,2, Hongwei Xu 1,2 , Xingmin Mu 1,3,*, Guangju Zhao 1,3, Peng Gao 1,3 and Wenyi Sun 1,3 1 State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China;
[email protected] (Q.L.);
[email protected] (H.X.);
[email protected] (G.Z.);
[email protected] (P.G.);
[email protected] (W.S.) 2 University of Chinese Academy of Sciences, Beijing 100049, China 3 State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China * Correspondence:
[email protected] Received: 19 April 2020; Accepted: 14 May 2020; Published: 18 May 2020 Abstract: Soil water and nutrients are major factors limiting crop productivity. In the present study, soil water use efficiency (WUE) and crop yield of millet and soybean were investigated under nine 1 fertilization regimes (no nitrogen (N) and no phosphorus (P) (CK), 120 kg ha− N and no P (N1P0), 240 1 1 1 1 kg ha− N and no P (N2P0), 45 kg ha− P and no N (N0P1), 90 kg ha− P and no N (N0P2), 120 kg ha− 1 1 1 1 1 N and 45 kg ha− P (N1P1), 240 kg ha− N and 45 kg ha− P (N2P1), 120 kg ha− N and 90 kg ha− P 1 1 (N1P2), 240 kg ha− N and 90 kg ha− P (N2P2)) in the Loess Plateau, China.