Di Yunfei, Gao Yu, Yang Haibo, Yan Dong, Tang Yuzhe, Zhang Weijian, Hu Yuncai, Li Fei
College of Resources and Environmental Sciences, Inner Mongolia Agricultural University, Hohhot, China.
Inner Mongolia Key Laboratory of Soil Quality and Nutrient Resources, Key Laboratory of Agricultural Ecological Security and Green Development at Universities of Inner Mongolia Autonomous Region, Hohhot, China.
Front Plant Sci. 2024 Dec 4;15:1476710. doi: 10.3389/fpls.2024.1476710. eCollection 2024.
Analyzing the effects of nitrogen (N) fertilizer application and water management on the carbon (C) and N footprints is vital to maize production systems.
This study conducted field experiments from 2019-2020 involving flood- and drip-irrigated maize production systems in Northwest China to analyze N and C footprints (NF and CF, respectively) based on the life cycle assessment (LCA). The N fertilizer treatments studied included no N fertilizer application (Control), optimized N management (OM), optimized N management incorporated with urease inhibitor (OMI, UI), and farmer practice (FP).
The maize grain yields under flood irrigation afforded by OMI (12.3 t ha) and FP treatments (13.4 t ha) were significantly higher than that of OM treatment (11.0 t ha). But maize grain yields of the OM (12.1 t ha), OMI (12.5 t ha), and FP treatments (12.5 t ha) showed no significant difference under drip irrigation although less N was applied to OM and OMI. The OMI treatment had better environmental effects than the OM treatment under both flood and drip irrigation. Applying N fertilizer with UI increased N use efficiency (NUE) and reduced N losses under flood irrigation. The reactive N (Nr) losses, greenhouse gas (GHG) emissions, NF, and CF of OMI treatment were 43.9%, 45.3%, 35.7%, and 37.4% lower under flood irrigation (77.6 kg N ha, 4499.9 kg CO2 eq ha, 6.7 kg N t, and 387.7 CO2 eq N t) and 43.3%, 37.1%, 43.2%, and 37.1% lower under drip irrigation (57.8 kg N ha, 4144.3 kg CO2 eq ha, 4.7 kg N t, and 332.7 CO2 eq N t) compared to the FP treatment. The Nr losses, GHG emissions, NF, and CF of drip irrigation were lower than those of flood irrigation. According to the analysis of driven indicators, the N leaching, electricity for irrigation, and NH volatilization were the most important contributors to the NF; the fertilizer, electricity for irrigation, and NO emissions were the dominant factors controlling the CF. The environmental impact of the OMI treatment was less than that of the OM and FP treatments. Therefore, integrating better N management practices and efficient irrigation methods can significantly reduce environmental impacts while maintaining yields in maize cultivation.
分析氮肥施用和水分管理对碳足迹和氮足迹的影响对于玉米生产系统至关重要。
本研究于2019 - 2020年在中国西北部进行了田间试验，涉及洪水灌溉和滴灌玉米生产系统，基于生命周期评估（LCA）分析氮足迹和碳足迹（分别为NF和CF）。所研究的氮肥处理包括不施氮肥（对照）、优化氮管理（OM）、结合脲酶抑制剂的优化氮管理（OMI，UI）以及农民实践（FP）。
在洪水灌溉下，OMI处理（12.3吨/公顷）和FP处理（13.4吨/公顷）的玉米籽粒产量显著高于OM处理（11.0吨/公顷）。但在滴灌条件下，尽管OM和OMI施氮量较少，其玉米籽粒产量（分别为12.1吨/公顷、12.5吨/公顷）与FP处理（12.5吨/公顷）无显著差异。在洪水灌溉和滴灌条件下，OMI处理的环境效应均优于OM处理。在洪水灌溉下，施用含脲酶抑制剂的氮肥提高了氮素利用效率（NUE）并减少了氮素损失。与FP处理相比，OMI处理在洪水灌溉下（77.6千克氮/公顷、4499.9千克二氧化碳当量/公顷、6.7千克氮/吨、387.7二氧化碳当量氮/吨）的活性氮（Nr）损失、温室气体（GHG）排放、NF和CF分别降低了43.9%、45.3%、35.7%和37.4%；在滴灌下（57.8千克氮/公顷、4144.3千克二氧化碳当量/公顷、4.7千克氮/吨、332.7二氧化碳当量氮/吨）分别降低了43.3%、37.1%、43.2%和37.1%。滴灌的Nr损失、GHG排放、NF和CF均低于洪水灌溉。根据驱动指标分析，氮淋溶、灌溉用电和氨挥发是NF的最重要贡献因素；肥料、灌溉用电和一氧化氮排放是控制CF的主要因素。OMI处理的环境影响小于OM和FP处理。因此，在玉米种植中整合更好的氮管理措施和高效灌溉方法可在保持产量的同时显著降低环境影响。
