中国农业科学2026，Vol.59Issue(6)：1255-1271,17.DOI:10.3864/j.issn.0578-1752.2026.06.009
稻田土壤不同粒级团聚体有机碳组分及CO2排放对长期施肥的响应
Characteristics of Organic Carbon Fractions and Carbon Dioxide Emissions of Different Size Aggregates in Rice Field Soils in Response to Long-Term Fertilization
摘要
Abstract
[Objective]This study aimed to investigate the dynamic characteristics of organic carbon(OC)and its fractions,carbon dioxide(CO2)emissions in different particle size aggregates under different fertilization regimes in paddy soil,and to analyze the influencing factors,so as to provide a scientific foundation for enhancing carbon sequestration and CO2 emission reduction in paddy soils from an aggregate perspective.[Method]Based on a soil incubation experiment,and using dichromate volumetric method,physical separation method and headspace periodic gas collection-gas chromatography,the OC and its fractions,CO2 emission characteristics of different particle size aggregates(<0.25 mm,0.25-1 mm,1-2 mm)were comparatively analyzed under different fertilization treatments(no fertilization,CK;conventional fertilization,NPK;and 50%substitution for 50%nitrogen fertilizers,HOM).[Result](1)The NPK treatment decreased OC content in 1-2 mm aggregates compared with the CK.In contrast,compared with NPK,the OC content of aggregates treated with HOM treatment increased by 5.8%to 29.4%,respectively.Both fertilization treatments(NPK and HOM)significantly enhanced the content of particulate organic carbon(POC)in 0.25-1 mm and 1-2 mm aggregates,with increases of 37.4%-79.6%and 4.3%-47.8%compared with CK,respectively,and HOM facilitated the turnover of mineral-associated organic carbon(MAOC)from 1-2 mm to<0.25 mm aggregates.(2)There were significant differences in the correlations between POC,MAOC,and OC across various aggregate particle sizes.For<0.25 mm aggregates,both POC and MAOC exhibited significantly positive correlations with OC content.For 0.25-1 mm aggregates,a significant positive correlation existed between MAOC and OC content.For 0.25-1 mm aggregates,a significant positive correlation existed between POC and OC content.(3)During the incubation experiment period,cumulative CO2 emissions of<0.25 mm aggregates were the lowest,which significantly reduced by 51.0%-83.7%and 23.1%-89.9%compared with 0.25-1 mm and 1-2 mm aggregates,respectively.Compared with NPK,HOM treatment significantly reduced the cumulative CO2 emissions in<0.25 mm and 0.25-1 mm aggregates by 146.27 and 364.27 g·kg-1,respectively,which was related to the changes in organic carbon fractions and the increase of aggregate pH and C/N under HOM treatment.[Conclusion]Different fertilization regimes have altered the OC and its fractions,CO2 emissions in different particle size aggregates.In detail,organic substitution promoted the accumulation of OC in aggregates,significantly increasing the POC content in 0.25-1 mm and 1-2 mm aggregates.Concurrently,it promoted the transfer of MAOC from 1-2 mm to<0.25 mm aggregates,while significantly reducing the CO2 emissions in<0.25 mm and 0.25-1 mm aggregated relative to conventional fertilization.Overall,organic substitution for 50%nitrogen fertilizers was beneficial for reducing the CO2 emissions of<0.25 mm and 0.25-1 mm aggregates in paddy field and enhancing the stability of organic carbon.关键词
长期施肥/土壤团聚体/有机碳组分/CO2排放/有机替代/稻田Key words
long-term fertilization/aggregates/organic carbon fraction/CO2 emissions/organic substitution/rice field引用本文复制引用
李星宇,黄容,鲜一鸣,田娇娇,马晓瑾,杨乔茜,李冰,王昌全..稻田土壤不同粒级团聚体有机碳组分及CO2排放对长期施肥的响应[J].中国农业科学,2026,59(6):1255-1271,17.基金项目
国家重点研发计划(2022YFD1901605)、四川省国际科技创新合作项目(2025YFHZ0142)、四川特色经作创新团队(SCCXTD-2025-12) （2022YFD1901605）
