关键词: 华北平原, 有机肥, 土壤固碳速率, N₂O, 模型

Abstract: 【Objective】Greenhouse gas (GHGs) emissions caused by agricultural activities have become one of the most important factors causing global warming. The North China Plain is a main food production region in China, optimizing the fertilization strategy in the North China Plain is of great significance to reduce GHGs emissions and mitigate climate change.【Method】Based on long-term experiment, this study used the validated process-based model-SPACSYS, combined with regional database and ArcGIS, clarified the spatial characteristics of average annual soil organic carbon sequestration rate (?SOC), average annual N₂O emission and average annual net global warming potential (NGWP) under three long-term fertilization scenarios (equal nitrogen fertilization), namely, chemical fertilizers only (NPK), 50% of chemical fertilizers combined with 50% of manure (NPKM(5:5)) and 30% of chemical fertilizers combined with 70% of manure (NPKM (3:7) ) from dry land in the North China Plain from 2010 to 2050.【Result】The average annual soil organic carbon sequestration rate from dry land in the North China Plain was higher in the east and lower in the west, and the higher regions mainly included Jiangsu and Shandong provinces. Correlation analysis showed that there was a significant negative correlation between ?SOC and initial soil organic carbon content. Stepwise linear regression analysis further indicated that initial soil organic carbon content, mean annual temperature and soil pH were three important factors affecting ?SOC, which accounted for 24% of the variation of ?SOC. The average annual N₂O emission was higher in the central part of the North China Plain, lower in the north and south, and the higher regions included parts of Shandong Province and Jiangsu Province. Correlation analysis showed that there was a significant positive correlation between average annual N₂O emission and initial soil organic carbon content. In general, compared with NPK, NPKM(5:5) and NPKM(3:7) both increased ?SOC and decreased soil N₂O emission from dry land in the North China Plain, of which ?SOC（233 and 236 kg C·hm^-2·a^-1)）increased by 79% and 82%, respectively, the average annual N₂O emission（15.8 and 14.4 kg N·hm^-2·a^-1)）decreased by 21% and 28%, respectively. As a result, NGWP（6.6 and 5.9 t CO₂-equivalent·hm^-2·a^-1)）decreased by 26% and 34%, respectively.【Conclusion】Compared with the application of chemical fertilizers, long-term application of chemical fertilizers combined with manure is beneficial to soil carbon sequestration, soil N₂O emission reduction and mitigation of glowing warming from dry land in the North China Plain over the long-term.

Key words: North China Plain; manure; soil organic carbon sequestration rate; N₂O, model