DNDC模型耦合遥感技术的保护性耕作下土壤有机碳模拟  

Soil organic carbon simulation under conservation tillage using DNDC model coupled with remote sensing technology

作　　者：刘泓君 许昭辉 周永馨 孙君龄 万炜[3] 刘忠 LIU Hongjun;XU Zhaohui;ZHOU Yongxin;SUN Junling;WAN Wei;LIU Zhong(College of Land Science and Technology,China Agricultural University,Beijing 100193,China;Key Laboratory of Arable Land Conservation in North China,Ministry of Agriculture and Rural Affairs,Beijing 100193,China;Key Laboratory of Poyang Lake Environment and Resources Utilization,Ministry of Education,School of Resources&Environment,Nanchang University,Nanchang 330031,China)

机构地区：[1]中国农业大学土地科学与技术学院,北京100193 [2]华北耕地保育农业农村部重点实验室,北京100193 [3]南昌大学资源与环境学院,鄱阳湖环境与资源利用教育部重点实验室,南昌330031

出　　处：《农业工程学报》2024年第9期108-118,共11页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划项目(2022YFD150070101);国家自然科学基金青年科学基金项目(42301091)。

摘　　要：不同耕作措施会改变土壤有机碳储量,影响农田生态系统的碳收支。揭示自实行保护性耕作以来农田土壤有机碳的响应规律,对增加土壤碳库具有重要意义。该研究基于遥感反演技术耦合DNDC(denitrification-decomposition)模型,从县域和栅格尺度,精细刻画保护性耕作下2000-2020年吉林省土壤有机碳密度(soil organic carbon density,SOCD)的空间分布格局,并模拟不同秸秆还田情景下SOCD增长潜力。结果表明:1)20 a间土壤有机碳储量由6.08×10^(8)t增加到1.22×10^(9)t,增量主要与耕地面积扩大相关。县域尺度SOCD在4.46~98.09 t/hm^(2),栅格尺度SOCD在3.34~139.2 t/hm^(2),呈现中高北低的格局。2)保护性耕作对表层土的影响更大,0~10 cm土层的SOCD增长率最高达4.4%,>10~20 cm土层增长率最高为0.09%。3)吉林西南及中部具有巨大的SOCD增长潜力,达0.24~0.57 t/hm^(2)。研究结果可为保护性耕作政策制定提供科学参考。Farming practices can contribute to the soil organic carbon storage in the carbon budget of farmland ecosystems.This study aims to determine the dynamic response pattern of conservation tillage to the soil organic carbon.The density of soil organic carbon under conservation tillage was collected from the cornfield in Jilin Province,China from 2000 to 2020 at the county and grid scales.The"golden corn belt"in Jilin Province was taken as the study area,and the spring corn was selected as the research object.Remote sensing inversion was used to couple the Denitrification-Decomposition(DNDC)model.Firstly,the crop residue coverage was inverted using remote sensing.The input parameter of the model was selected to optimize the residue management module in the DNDC model.Secondly,the local soil properties were combined with the meteorology and farmland measure data.Regional simulation was implemented using two division units,in order to accurately depict the spatiotemporal dynamic evolution of soil organic carbon density under conservation tillage.In addition,the potential of conservation tillage was further explored to increase the soil carbon pools.The simulation was finally performed on the growth potential of soil organic carbon density under different straw return scenarios,according to the parameters of crop residue coverage in the DNDC model.The results show:1)The DNDC model was feasible in this case.The R2 value reached 90%for the soil organic carbon under different farmland measures,and the relativer root mean square error values were all within 10%.The relatively better performance was used to simulate the local soil organic carbon density and long-term forecasts.2)Soil organic carbon storage in cornfields increased significantly over the past 20 years,from 6.08×10^(8)to 1.22×10^(9)t.The reason was closely related to the expansion of the cultivated land area.The soil organic carbon density varied between 4.46 and 98.09 t/hm^(2) at the county scale,while there was a variation between 3.34 and 139.2 t/hm^(2) at

关 键 词：秸秆 遥感 碳 DNDC模型 情景模拟 有机碳密度 吉林省 

分 类 号：S153.6[农业科学—土壤学]