1. Key Laboratory of Crop Physio-Ecology and Tillage Science in the Northwestern Loess Plateau, Ministry of Agriculture, Northwest A&F University, Yangling, Xianyang 712100, China
2. Institute of Water Saving Agriculture in Arid Areas of China, Northwest A&F University, Yangling, Xianyang 712100, China
3. College of Agronomy, Northwest A&F University, Yangling, Xianyang 712100, China