Integrated impacts of irrigation and nitrogen management for balancing winter wheat yield and greenhouse gas emissions

• Published in: Crop and Environment Vol. 2; no. 3; pp. 126 - 136
• Main Authors: Shen, Hongzheng, Li, Shilei, Sun, Kexin, Gao, Yunhe, Liu, Yanxin, Ma, Xiaoyi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2023; Elsevier
• Subjects: Global warming potential; Greenhouse gas; Greenhouse gas emission intensity; Irrigation; Nitrogen reduction/replacement; Irrigation; Global warming potential; Greenhouse gas emission intensity; Nitrogen reduction/replacement; Greenhouse gas
• ISSN: 2773-126X; 2773-126X
• DOI: 10.1016/j.crope.2023.06.001

Irrigation and nitrogen (N) input are effective methods of balancing crop yields and greenhouse gas (GHG) emissions. However, the effects of irrigation and N management on the GHG emission of winter wheat production systems have not yet been well documented. Therefore, we conducted 2-year field experiments on winter wheat and studied the effects of irrigation and N reduction/replacement on GHG emissions, grain yield, global warming potential (GWP), and GHG emission intensity (GHGI). The winter wheat was irrigated once or twice with 60 or 90 ​mm each time. Five N reduction/replacement treatments were no N application (CK), 25% traditional urea (U) reduction (75%U), traditional U (U), 25% reduction in polymer-coated U (PCU), and 25% reduction in traditional U combined with organic fertilizers (U ​+ ​OM). The results indicated that N reduction/replacement significantly reduced N2O emissions, but had no significant effect on CH4 emissions. Soil water-filled pore space was the same key factor affecting the emission fluxes of N2O and CH4. Soil temperature significantly affected the fluxes of CH4 (P ​< ​0.001). Irrigation treatment did not exhibit a significant effect on grain yield, but high irrigation input increased the GWP and GHGI. Compared with U, the grain yield of CK, 75%U, PCU, and U ​+ ​OM increased by −46%, −9.2%, −1.8%, and 5.4%, respectively; GWP decreased by 35.9%, 11.6%, 7.3%, and 2.7%, respectively; and GHGI decreased by −22.1%, 3.1%, 6.0%, and 8.0%, respectively. Therefore, sustainable production goals of increasing grain yield and reducing GHG emissions were achieved with N reduction/replacement using U + OM and low irrigation input of 60 ​mm.