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西北農林科技大學水土保持研究所沈玉芳研究員團隊根據我國西北半乾旱地區春玉米系統的糧食產量、經濟效益和環境效益對不同氮肥管理措施進行了評價。相關成果發表於Journal of Cleaner Production（IF=7.246）。
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•The mixture of controlled-release and normal urea (CU) is beneficial to net return.
•One-time application of CU changed the pattern of N2O emissions.
•Straw return increased CO2 and N2O emissions, by 35% and 51%, respectively.
•Straw return increased SOC and reduced carbon footprint, by 8% and 50%, respectively.
For a long time, nitrogen (N) management for high-yielding maize (Zea mays L.) has been a severe challenge. The N supply must maximize yield while minimizing environmental impact. In response to the above problems, we evaluated different approaches to nitrogen fertilizer management based on grain yield, economic benefits and environmental benefits of spring maize systems from 2017 to 2019 in a semiarid area of northwestern China. The four treatments included solid granular urea with a split application (UR), one-time application of a mixture of controlled release and solid granular urea (CU), straw return with the combination of controlled release and solid granular urea (CUS) and control (CK). From the perspective of agricultural production, compared with the CK, high yields (>15 Mg ha−1) were guaranteed in the other treatments. Considering both the environment and the economy, compared with the UR treatment, the CU treatment not only improved the economic efficiency of maize cultivation (increased by 4.9%–12.1%) but also significantly decreased the net global warming potential (NGWP) and carbon footprint (CF) (decreased by 21.1–21.7% and 17.8–23.1%, respectively). At the same time, the CU treatment optimized the proportions of N2O emissions at different growth stages and reduced the risk of emissions caused by high temperatures and rainfall in the middle and late stages of maize growth. Compared to the CU treatment, although the CUS treatment increased CO2 and N2O emissions (increased by 35% and 51%, respectively), the accumulation of soil organic carbon (SOC) was enhanced by straw return, which offset the negative impact of the increase in greenhouse gas emissions and significantly reduced the NGWP and CF compared to values for the other three treatments (decreased by 51% and 50%, respectively). With a comprehensive consideration of environmental impacts and economic benefits, the combination of solid granular urea (SGU) and controlled release urea (CRU) with the straw return is an environmentally friendly, high-yielding, high-economic benefit and low-emissions production technology for arid and semiarid areas.
長期以來，高產玉米的氮素管理一直是一個嚴峻的挑戰。氮素供應應當最大限度地提高產量，同時儘量減少對環境的影響。針對上述問題，本文根據2017—2019年我國西北半乾旱地區春玉米系統的糧食產量、經濟效益和環境效益對不同氮肥管理措施進行了評價。4個處理包括分次施用固體顆粒尿素（UR）、控釋尿素與固體顆粒尿素混合一次性施用（CU）、秸稈還田、控釋尿素與固體顆粒尿素組合施用（CUS）和對照處理（CK）。從農業生產的角度來看，與對照相比，其他處理實現了較高的產量（>15 Mg·ha−1）。從環境和經濟兩個方面來看，與UR處理相比，CU處理不僅提高了玉米種植的經濟效率（增加了4.9%-12.1%），而且顯著降低了淨全球增溫潛勢（NGWP）和碳足跡（CF）（分別減少了21.1%-21.7%和17.8%-23.1%）。同時，CU處理優化了不同生長階段N2O的排放比例，降低了玉米生長中後期由高溫和降雨造成的排放風險。與CU處理相比， CUS處理雖然增加了CO2和N2O （分別增加了35%和51%），但由於秸稈還田作用，增加了土壤有機碳（SOC）的積累，這抵消了溫室氣體排放增加的負面影響，相比其他三個處理顯著降低了NGWP和CF值（分別下降了51%和50%）。固體顆粒尿素（SGU）、控釋尿素（CRU）與秸稈還田相結合，能夠綜合考慮環境影響和經濟效益，是能夠實現乾旱半乾旱地區環保、高產、高效益、低排放的生產技術。
責任編輯：宋瀟
校對和審核：張陽 王農
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