摘要
为揭示有机碳变化的关键影响因素并为北京地区实现固碳减排目标提供科学依据,利用北京怀柔区前桥梓村玉米田2016-2019年土壤有机碳(soil organic carbon,SOC)实测数据对反硝化-分解模型(denitrification-decomposition model,DNDC)进行验证,选取气候、土壤及秸秆还田等主要影响因子对验证后的DNDC模型进行敏感性分析,模拟了2种典型浓度路径(RCP8.5、RCP4.5)下该农田未来(至2100年)土壤有机碳变化情况。结果显示:经过校验后的DNDC模型可较好地模拟该玉米田SOC变化;初始有机碳含量及秸秆还田率是SOC变化的主要影响因素;RCP8.5及RCP4.5下SOC含量增加明显,土壤碳库在2100年达到平衡,2100年有机碳含量分别达到27.70、29.03 g/kg,分别较初始有机碳含量上升197.85%和212.15%。结果表明,DNDC模型可用于该研究区玉米田有机碳变化预测,该农田持续采用当前施肥和秸秆还田管理方式可实现土壤持续固碳。
土壤是陆地生态系统的最大碳库,其碳库含量约是大气碳库的3倍,土壤碳库含量的微小变化将导致大气CO2浓度的明显波
反硝化-分解模型(denitrification-decomposition model,DNDC)起源于美国,由2个部分共6个模块构
2021年,北京地区玉米播种面积已达到4.3万h
研究区属北京市农田长期定点监测地块,位于北京市怀柔区桥梓镇前桥梓村(116.57°E,40.28°N),属于半湿润大陆性季风气候,冬季寒冷少雪,夏季暖热湿润,年均降雨量约600~700 mm,海拔67.7 m,无霜期205 d。
研究区农田为农户所有,种植模式为春玉米连作,无重复。农田初始土壤理化性质为有机质15.97 g/kg、容重1.41 g/c
本研究应用DNDC9.5版本,模型需要输入的参数主要包括气象数据、土壤数据以及农田管理数据,数据来源如下:
1)气象数据。研究区2016-2019年的气象数据,包括日平均气温和日降水量等数据,来源于RP5国际交换气象站(http://rp5.ru),其实际气象数据来源于各地气象站,具有较高的数据可靠
此外,依据IPCC第5次评估报告中提出的4种典型浓度路
2)土壤数据。农田初始SOC、全氮、速效磷和速效钾含量为研究区农田0~20 cm土壤耕层实测值,其中,SOC测定方法为重铬酸钾-外加热法(NY/T1121.6-2006),全氮测定方法为凯氏法(HJ 717-2014),速效磷测定方法为Olsen-P法(HJ 704-2014),速效钾测定方法为乙酸铵提取-火焰光度法(NY/T 889-2004);土壤质地通过现场实际调查获得;土壤pH和容重信息来源于世界土壤数据库。
3)田间管理数据。研究区的农田管理数据(包括农作物种类、种植及收获日期、肥料种类、施肥量、灌溉量及秸秆还田量等)来源于北京市农田长期定位监测数据库中的实际调查监测数据。
降低DNDC模型模拟结果的不确定度是应用模型的重要前
XRMSE | (1) |
(2) |
(3) |
式(
以研究区的气象条件、土壤特征和农田管理方式为基准情境进行DNDC模型的敏感性分析,通过调整参数,分析SOC固定对不同输入参数的敏感性。本研究采用独立参数扰动
(4) |
本研究中各因子的基准值及变更情况如
参数 Parameters | 基准值 Base values | 更改值 Change values |
---|---|---|
年均温度/℃ Mean annual temperature | 13.89 | 11.11、16.68 |
年均降雨量/mm Mean annual precipitation | 596 | 476.8、715.2 |
降雨氮质量浓度/(mg/L) N concentration in precipitation | 3.5 | 2.8、4.2 |
大气CO2质量浓度/(g/ CO2 concentration in atmosphere | 400.375 | 320.29、480.44 |
黏粒含量/% Clay content | 19 | 15、23 |
初始有机碳含量/(g/kg) Initial SOC content | 9.3 | 7.44、11.16 |
酸碱度 pH | 8.0 | 6.4、9.6 |
秸秆还田率/% Straw returning rate | 100 | 25、75 |
化肥用量/(kg/h Chemical fertilizer amount | 348.93 | 418.72、279.14 |
由于土壤有机质转换周期较
(5) |
式中,CSOC2为试验末期有机碳含量,g/kg;CSOC1为试验初期有机碳含量,g/kg;n为试验年限,a。
通过试错法不断对模型参数予以校正,验证结果如

图1 SOC含量模拟值与观测值对比
Fig.1 The comparison of simulated and measured value of SOC
对SOC变化的主要影响因子进行敏感性分析,结果(
测试参数 Testing parameters | 参数变化范围 Rangeof parameters | 年均土壤固碳速率/(g/(kg·a)) Annual SOC sequestration rate | 敏感性指数 Sensitivity index |
---|---|---|---|
氮肥用量/(kg/h | 279.14~418.72 | 0.60~0.54 | -0.26 |
秸秆还田率/% Straw returnning rate | 25~75 | 0.10~0.39 | 1.18 |
年均温度/℃ Mean annual temperature | 11.11~16.68 | 0.61~0.55 | -0.25 |
年均降雨量/mm Mean annual precipitation | 476.8~715.2 | 0.56~0.58 | 0.10 |
降雨氮质量浓度/(mg/L) N concentration in precipitation | 2.8~4.2 | 0.56~0.56 | 无影响No effect |
大气CO2质量浓度/(g/ | 320.29~480.44 | 0.54 | 0.14 |
黏粒含量/% Clay content | 15~23 | 0.58~0.55 | -0.63 |
初始有机碳含量/(g/kg) Initial SOC content | 7.44~11.16 | 0.17~0.96 | 3.51 |
pH | 6.4~9.6 | 0.55~0.58 | 0.14 |
1)怀柔未来气象变化。2016-2100年怀柔地区气温和降水量变化趋势如

图2 2016-2100年典型浓度路径RCP4.5和RCP8.5情境下气温(A)和降水量(B)变化
Fig.2 Changes of temperature(A) and precipitation(B) under typical concentration pathways RCP4.5 and RCP8.5 during 2016 and 2100
2)未来有机碳变化。利用DNDC模型对不同典型浓度路径下研究区SOC含量变化进行模拟预测,结果如

图3 不同典型浓度路径下农田SOC含量变化模拟预测结果
Fig.3 Simulation and prediction results of farmland SOC under different RCPs
根据
关于DNDC模型对我国不同生态气候区的适用情况,已有多位学者进行了研究,认为DNDC模型可以较好地实现对我国农田SOC含量变化的模拟预
本研究还得出,初始有机碳含量及秸秆还田率是影响该玉米田有机碳变化的主要影响因素。张钊
未来不同典型浓度路径下气候条件随时间的变化呈现出不同的变化趋势(
本研究得出,RCP4.5路径比RCP8.5具有较高的土壤固碳潜力,分别为0.25 g/(kg·a)和0.23 g/(kg·a)。然而,贺美
值得注意的是,RCP4.5和RCP8.5浓度路径下分别在第28年和第24年时出现有机碳含量的小幅下降(
本研究首先对模型参数进行了校正,以提高模型模拟结果的可靠性。研究结果表明该模型可以较好地模拟农田SOC含量变化。通过进一步开展敏感性分析得出,SOC变化对初始有机碳含量及秸秆还田率等参数较为敏感。DNDC模型模拟结果表明,研究区采用当前的施肥管理措施,在RCP4.5和RCP8.5这2种典型浓度路径下,农田SOC含量变化均随时间推进而呈现出增加的趋势,但有机碳含量增速逐渐下降,第77年时土壤碳库达到平衡。同时,未来降水波动可能会导致农田SOC含量损失,需关注降水对农田土壤固碳管理措施的影响。综上,在农业生产实际过程中,实施秸秆还田、因地制宜地制定农田土壤管理措施,可促进农田土壤碳库增加。
参考文献References
马子钰,马文林.施肥对中国农田土壤固碳影响效应研究[J].土壤,2022,54(5):905-911. MA Z Z,MA W L.Effects of fertilization on soil organic carbon in cropland of China[J].Soils,2022,54(5):905-911 (in Chinese with English abstract). [百度学术]
李昊昱,孟兆良,庞党伟,等.周年秸秆还田对农田土壤固碳及冬小麦-夏玉米产量的影响[J].作物学报,2019,45(6):893-903.LI H Y,MENG Z L,PANG D W,et al.Effects of annual straw return model on soil carbon sequestration and crop yields in winter wheat-summer maize rotation farmland[J].Acta agronomica sinica,2019,45(6):893-903 (in Chinese with English abstract). [百度学术]
薛静,李旭强,陈军锋,等.不同降水年型下春玉米适宜秋浇模式的模拟研究[J].灌溉排水学报,2021,40(6):80-87.XUE J,LI X Q,CHEN J F,et al.Suitable irrigation scheduling for spring maize under different annual precipitation patterns in Hetao Irrigation District[J].Journal of irrigation and drainage,2021,40(6):80-87 (in Chinese with English abstract). [百度学术]
张凤,王世航,王军委.土壤有机碳模型研究进展[J].宜春学院学报,2019,41(9):12-18.ZHANG F ,WANG S H,WANG J W. Research progress of soil organic carbon model[J].Journal of Yichun University,2019,41(9):12-18 (in Chinese with English abstract). [百度学术]
王多斌,籍常婷,林慧龙.基于DNDC模型的高寒草甸土壤有机碳含量动态研究[J].草业学报,2019,28(12):197-204. WANG D B,JI C T,LIN H L.A ‘denitrification-decomposition’(DNDC) model evaluation of alpine meadow soil carbon response to climate change[J].Acta praculturae sinica,2019,28(12):197-204 (in Chinese with English abstract). [百度学术]
张守都,栗岩峰,李久生.基于DNDC模型的东北半湿润区膜下滴灌玉米施肥制度优化[J].中国水利水电科学研究院学报,2018,16(2):113-121.ZHANG S D,LI Y F,LI J S.Optimization of fertilizing schedule for maize with mulched drip irrigation in sub-humid region of Northeast China DNDC model[J].Journl of China Institute of Water Resources and Hydropower Research,2018,16(2):113-121 (in Chinese with English abstract). [百度学术]
李强,李建国,张忠启,等.基于DNDC模型与二分法的滨海盐渍土水稻最佳施氮量研究[J].水土保持通报,2018,38(3):167-173. LI Q,LI J G,ZHANG Z Q,et al.Optimizing N-fertilizer inputs for rice production in coastal saline based on a biogeochemical model and dichotomy[J].Bulletin of soil and water conservation,2018,38(3):167-173 (in Chinese with English abstract). [百度学术]
LIAO Y,WU W L,MENG F Q,et al.Impact of agricultural intensification on soil organic carbon:a study using DNDC in Huantai County,Shandong Province,China[J].Journal of integrative agriculture,2016,15(6):1364-1375. [百度学术]
ZHANG F,ZHANG W,LI M,et al.Is crop biomass and soil carbon storage sustainable with long-term application of full plastic film mulching under future climate change?[J].Agricultural systems,2017,150:67-77. [百度学术]
北京市统计局.北京统计年鉴2022[M].北京:中国统计出版社,2022.Beijing Municipal Statistics Bureau.Beijing statistical yearbook 2022[M].Beijing:China Statistics Press,2022 (in Chinese). [百度学术]
唐豪.基于高斯模型的在航船舶尾气扩散研究[D].南京:东南大学,2021. TANG H.Research on exhaust gas diffusion of ships at sea based on gaussian model[D].Nanjing:Southeast University,2021(in Chinese with English abstract). [百度学术]
LIU X,JU X,ZHANG Y,et al.Nitrogen deposition in agroecosystems in the Beijing area[J].Agriculture,ecosystems & environment,2006,113(1-4):370-377 (in Chinese with English abstract). [百度学术]
孙庆瑞,王美蓉.我国氨的排放量和时空分布[J].大气科学,1997,21(5):79-87. SUN Q R,WANG M R.Ammonia emission and concentration in the atmosphere over China[J].Scientia atmospherica sinica,1997,21(5):79-87(in Chinese with English abstract). [百度学术]
王长科,王跃思,刘广仁.北京城市大气CO2浓度变化特征及影响因素[J].环境科学,2003,(4):13-17. WANG C K,WANG Y S,LIU G R.Characteristics of atmospheric CO2 variations and some affecting factors in urban area of Beijing[J].Environmental science,2003,(4):13-17(in Chinese with English abstract). [百度学术]
王向一.我国双季稻区域温室气体排放模拟研究[D].上海:上海应用技术大学,2019. WANG X Y.Simulation of GHG emissions in cropping paddy field[D].Shanghai:Shanghai Institute of Technology,2019(in Chinese with English abstract). [百度学术]
HWANG W,KIM C,CHO K,et al.Characteristics of greenhouse gas emissions from rice paddy fields in South Korea under climate change scenario RCP-8.5 using the DNDC model[J].Pedosphere,2021,31(2):332-341. [百度学术]
宋佳珊.麦玉体系土壤有机碳和作物产量对长期施肥及气候变化的响应[D].杨凌:西北农林科技大学,2021. Response of soil organic carbon and crop yield to long-term fertilization and climate change in winter-wheat and summer-maize rotation[D].Yangling:Northwest A&F University,2021(in Chinese with English abstract). [百度学术]
贺美,王迎春,王立刚,等.应用DNDC模型分析东北黑土有机碳演变规律及其与作物产量之间的协同关系[J].植物营养与肥料学报,2017,23(1):9-19. HE M,WANG Y C,WANG L G,et al.Using DNDC model to simulate black soil organic carbon dynamics as well as its coordinate relationship with crop yield[J].Journal of plant nutrition and fertilizer,2017,23(1):9-19(in Chinese with English abstract). [百度学术]
乔帅帅,胡振华,魏征,等.DNDC模型在华北平原冬小麦区的率定和验证[J].中国农村水利水电,2018,(6):22-26. QIAO S S,HU Z H,WEI Z,et al.The calibration and validation of DNDC model in winter wheat regions of North China Plains[J].China rural water and hydropower,2018,(6):22-26(in Chinese with English abstract). [百度学术]
JIANG R,YANG J Y,DRURY C F,et al.Assessing the impacts of diversified crop rotation systems on yields and nitrous oxide emissions in Canada using the DNDC model[J/OL].Science of the total environment,2021,759:143433[2023-01-06].https://doi.org/10.1016/j.scitotenv.2020.143433. [百度学术]
薛静,毛萌,任理.DNDC模型在曲周试验站的参数灵敏度分析及率定[J].中国农业科学,2013,46(13):2695-2708. XUE J,MAO M,REN L.The parameter sensitivity analysis and calibration of DNDC model in Quzhou agricultural experiment station[J].Scientia agricultura sinica,2013,46(13):2695-2708(in Chinese with English abstract). [百度学术]
王德营,姚艳敏,司海青,等.黑土有机碳变化的DNDC模拟预测[J].中国生态农业学报,2014,22(3):277-283. WANG D Y,YAO Y M,SI H Q,et al.Using DNDC model to simulate and predict changes in black soil organic carbon[J].Chinese journal of eco-agriculture,2014,22(3):277-283(in Chinese with English abstract). [百度学术]
李晓菡,邹俊亮,武菊英,等.土壤呼吸和有机碳对增温的响应及其影响因素分析[J].地球与环境,2022,50(4):471-480.ZHANG X H,ZOU J L,WU J Y,et al.Responses of soil respiration and organic carbon to warming and their influencing factors[J]Earth and environment,2022,50(4):471-480(in Chinese with English abstract). [百度学术]
谢海宽,江雨倩,李虎,等.DNDC模型在中国的改进及其应用进展[J].应用生态学报,2017,28(8):2760-2770. XIE H K,JIANG Y Q,LI H,et al.Modification and application of the DNDC model in China[J].Chinese journal of applied ecology,2017,28(8):2760-2770(in Chinese with English abstract). [百度学术]
金琳,李玉娥,高清竹,等.DNDC模拟中国20年农田管理土壤碳变化[J].土壤通报,2010,41(5):1081-1085. JIN L,LI Y E,GAO Q Z,et al.Analysis of the change of soil carbon under cropland management in China between 1981 and 2000 by DNDC[J].Chinese Journal of soil science,2010,41(5):1081-1085(in Chinese with English abstract). [百度学术]
WANG L,QIU J,TANG H,et al.Modelling soil organic carbon dynamics in the major agricultural regions of China[J].Geoderma,2008,147(1/2):47-55. [百度学术]
张凡,李长生,王政.耕作措施对陕西耕作土壤碳储量的影响模拟[J].第四纪研究,2006,(6):1021-1028. ZHANG F,LI C S,WANG Z.Modeling the impacts of management alternatives on soil carbon storage of farmland in Shaanxi Province[J].Quaternary sciences,2006,(6):1021-1028(in Chinese with English abstract). [百度学术]
张钊,辛晓平.生物地球化学模型DNDC的研究进展与碳动态模拟应用[J].草地学报,2017,25(3):445-452. ZHANG Z,XIN X P.Reasearch progress of biogeochemistry model DNDC in carbon dynamic modeling[J].Acta agrestia sinica,2017,25(3):445-452(in Chinese with English abstract). [百度学术]
吕宏菲.基于DNDC模型对秸秆还田下土壤有机碳和作物产量的模拟研究[D].杨凌:西北农林科技大学,2020. LÜ H F.Simulation study on soil organic carbon and crop yield under straw resturning based on DNDC model[D].Yangling:Northwest A&F University,2020(in Chinese with English abstract). [百度学术]
朱明亚,潘毅群,沙华晶,等.气候变化条件下中国典型城市未来天气参数与建筑能源需求预测[J].建筑节能,2013,41(3):57-64. ZHU M Y,PAN Y Q,SHA H J,et al.Prediction of future weather data and building energy demand for representative cities in China under climate change[J].Journal of building energy efficiency,2013,41(3):57-64(in Chinese with English abstract). [百度学术]
XU C H,XU Y,et al.The pojection of temperature and precipitation over China under RCP scenarios using a CMIP5 multi-model ensemble[J].Atmospheric & oceanic science letters,2012,5(6):527-533. [百度学术]
杨黎,王立刚,李虎,等.基于DNDC模型的东北地区春玉米农田固碳减排措施研究[J].植物营养与肥料学报,2014,20(1):75-86. YANG L,WANG L G,LI H,et al.Modeling impacts of alternative farming management practices on carbon sequestration and mitigating N2O emissions from spring maize fields[J].Journal of plant nutrition and fertilizer,2014,20(1):75-86(in Chinese with English abstract). [百度学术]
颜学斌,王俊,王科锋,等.基于DNDC模型模拟的冬小麦田土壤有机碳和作物产量对地表覆盖的响应[J].干旱地区农业研究,2022,40(1):42-49. YAN X B,WANG J,WANG K F,et al.Responses of soil organic carbon and crop yield to surface mulching with straw and plastic film in winter wheat field using DNDC model[J].Agricultural research in the arid areas,2022,40(1):42-49(in Chinese with English abstract). [百度学术]