水氮耦合下黑土区稻田生态系统碳源汇效应分析  

Effect of Water and Nitrogen Coupling on Carbon Source and Sink of Paddy Ecosystem in Black Soil Area

作　　者：张忠学 薛里[1,2] 李铁成 齐智娟 王忠波[1,2] 周欣 ZHANG Zhongxue;XUE Li;LI Tiecheng;QI Zhijuan;WANG Zhongbo;ZHOU Xin(School of Water Conservancy and Civil Engineering,Northeast Agricultural University,Harbin 150030,China;Key Laboratory of Efficient Utilization of Agricultural Water Resources,Ministry of Agriculture and Rural Affairs,Northeast Agricultural University,Harbin 150030,China)

机构地区：[1]东北农业大学水利与土木工程学院,哈尔滨150030 [2]东北农业大学农业农村部农业水资源高效利用重点实验室,哈尔滨150030

出　　处：《农业机械学报》2023年第8期330-338,共9页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家重点研发计划项目(2022YFD2300303)。

摘　　要：为探寻不同水氮耦合方式对黑土区稻田生态系统碳平衡的影响,于2022年开展田间试验,试验设置常规淹灌(F)和稻作控制灌溉(C)两种灌溉模式,同时设置常规施氮水平(N,110 kg/hm~2)、减氮10%水平(N1,99 kg/hm~2)、减氮20%水平(N2,88 kg/hm~2)3种施氮水平,分析不同水氮耦合方式对水稻各器官干物质量、碳含量、稻田土壤呼吸CO_(2)排放通量和CH_(4)排放通量及两者排放总量的影响,并采用净生态系统碳收支(NECB)评价体系对黑土区稻田生态系统碳源汇效应进行分析。结果表明:不同水氮耦合方式下,各处理水稻穗固碳量与根固碳量分别占其总固碳量的26.61%~40.92%、24.63%~31.95%。相同施氮量下,稻作控制灌溉相较于常规灌溉能提高水稻各器官碳含量、干物质量。在水稻全生育期内,各处理CH_(4)排放通量呈现先增加后减小再增加的变化趋势,均在分蘖期与拔节孕穗期出现峰值;各处理土壤呼吸CO_(2)排放通量呈现单峰变化,在分蘖期出现峰值。相同灌溉模式下,除返青期外,各处理CH_(4)排放通量与土壤呼吸CO_(2)排放通量均随施氮量的减少而降低。相同施氮量下,稻作控制灌溉与常规灌溉相比降低了土壤呼吸CO_(2)排放通量及排放总量,但提高了CH_(4)排放通量及排放总量。不同水氮耦合方式下,水稻净初级生产力为4245.82~6958.19 kg/hm~2,穗净初级生产力最高、凋落物净初级生产力最低,分别占其水稻净初级生产力的42.88%~51.82%、3.19%~3.90%。相同施氮量下,稻作控制灌溉模式各处理水稻净初级生产力均大于常规灌溉模式,其中CN、CN1、CN2各处理净初级生产力较FN、FN1、FN2各处理分别增加11.17%、31.92%、2.98%。此外,不同水氮耦合方式下NECB均为正值,表示该黑土区稻田生态系统为净碳“汇”,其中CN1处理净碳收支(1082.87 kg/hm~2)显著高于其他各处理(P<0.05),这说明稻作控制灌溉模式下减氮10%处理的稻田生态系统�A field experiment was conducted to explore the effects of different water and nitrogen coupling methods on the carbon balance of paddy ecosystem in 2022.Two irrigation modes(conventional flooding irrigation(F) and rice-controlled irrigation(C)) and three nitrogen application levels(conventional nitrogen application-level(N,110 kg/hm~2),10% nitrogen reduction-level(N1,99 kg/hm~2) and 20% nitrogen reduction-level(N2,88 kg/hm~2)) were set up in the experiment.The effects of different water and nitrogen coupling on dry matter weight,carbon content,soil respiration CO_(2) emission flux,CH_(4) emission flux,and total emissions of both were analyzed.The net ecosystem carbon budget(NECB) evaluation system was used to analyze the carbon source and sink effect of ecosystem in black soil paddy fields.The results showed that under different water and nitrogen coupling modes,the carbon sequestration of rice panicles and roots accounted for 26.61%~40.92% and 24.63%~31.95% of the total carbon sequestration,respectively.Under the same nitrogen application rate,C can improve the carbon content and dry matter weight of rice organs compared with F.During the whole growth period of rice,the CH_(4) emission flux of each treatment showed a trend of increasing first,then decreasing before increasing,and peaked at tillering stage and jointing-booting stage.The soil respiration CO_(2) emission flux of each treatment showed a single peak variation,and the peak appeared at the tillering stage.Under the same irrigation mode,except for the regreening period,the CH_(4) emission flux and soil respiration CO_(2) emission flux of each treatment was decreased with the decrease of nitrogen application rate.Under the same nitrogen application rate,compared with rice control irrigation,F reduced soil respiration CO_(2) emission flux and total emission,but increased CH_(4) emission flux and total emission.Under different water and nitrogen coupling modes,the net primary productivity of rice was 4 245.82~6 958.19 kg/m~2,the net primary productivity o

关 键 词：黑土区稻田 水氮耦合 净生态系统碳收支 净初级生产力 

分 类 号：S511.41[农业科学—作物学] S365