不同土地利用和施肥方式下黑土碳平衡的研究  

Estimation of carbon balance under different land uses and long-term fertilizations in black soils of Northeast China

作　　者：李海波[1,2] 韩晓增[2] 

机构地区：[1]吉林农业科技学院植物科学学院吉林132101 [2]中国科学院东北地理与农业生态研究所海伦农田生态系统国家野外观测研究站中国科学院黑土区农业生态重点实验室哈尔滨150081

出　　处：《中国生态农业学报》2014年第1期16-21,共6页Chinese Journal of Eco-Agriculture

基　　金：国家重点基础研究发展计划(973计划)项目(2010CB134509,2011CB100506);国家自然科学基金项目(40971152);黑龙江省自然科学重点基金项目(ZD200904)资助

摘　　要：本研究进行了东北黑土不同土地利用(草地GL、裸地BL)与农田施肥管理方式(无肥NF、化肥NPK及化肥+有机肥处理NPKOM)下草本植物与作物净初级生产力(NPP)和净生态系统生产力(NEP)以及土壤碳排放的估算,目的是揭示自然与农田生态系统及经过土壤大气界面的碳收支平衡。土壤生长季碳排放总量(Rgs)、全年碳排放总量(Rann)以及全年微生物异养呼吸总量(Rm)以如下顺序递减:NPKOM>GL>NPK>NF>BL,5个处理之间存在显著差异(P<0.05),但是草地与农田化肥+有机肥处理之间差异不显著(P>0.05)。净初级生产力表现:GL>NPKOM>NPK>NF>BL,5个处理之间存在显著差异(P<0.05)。草地总生物量及固碳量显著高于农田各处理(P<0.05),草地NPP总量与农田各处理相比增加32%~96%。化肥+有机肥处理和化肥处理NPP总量比无肥处理高46%和49%。草地与农田的NEP均为正值,表明草地与农田在生态系统尺度上均是大气CO2的"汇"。对大气土壤界面碳平衡的分析表明,当前管理方式下,草地土壤是大气碳库的净汇,而裸地和农田土壤是净源。农田不同施肥处理土壤有机碳含量呈下降趋势,但增加有机肥的投入可增强土壤的固碳容量,达到新的碳平衡。Soil carbon pool is an important component of terrestrial ecosystem with higher carbon storage and the atmospheric CO2 pool compensation capacity via CO2 flux from soil surface, which is of great significance to global carbon cycle and carbon budget. Therefore tiny changes in soil carbon pool have a strong impact on atmospheric CO2 concentration. This study aimed to assess carbon budget at ecosystem scale by comparing soil carbon effiux, net primary productivity （NPP） and net ecosystem productivity （NEP）. The assessment was done through soil-atmosphere interface analysis as influenced by land use change and long-term fertilization in croplands of maize-soybean-wheat rotation system in the black soils of Northeast China. The land use types were grassland （GL） and bareland （BL） and farmlands with three long-term fertilization patterns including non-fertilization （NF）, nitrogen, phosphorus and potassium fertilization （NPK）, and organic manure amended NPK （NPKOM）. Static chambers used to collect gas samples in cropland treatments were of two types -- one used to collect gas samples from whole soils and the other to collect gas samples from non-rhizospheric soils. Soil carbon flux was determined by CO2 concentration detection in a gas chromatograph （Shimadzu GC--2010） equipped with a flame ionization detector （FID）. The annual cumulative CO2 flux was calculated based on soil CO2 flux rate. The three-year averaged annual carbon flux （Ro,n） and annual microbial respiration （Rm） decreased in the order of NPKOM 〉 GL 〉 NPK 〉 NF 〉 BL. In addition, significant difference was noted in R~,n and Rm among the five experimental treatments （P 〈 0.05）. However, no significant difference was observed between grassland and NPKOM plots （P 〉 0.05） in terms of soil CO2 fluxes. For cropland treatments, Rann and R,, were significantly （P 〈 0.05） higher in NPKOM than in NPK and NF. However, no significant difference was found in annual carbon flux in root-free soils （R

关 键 词：黑土 生态系统 土壤碳平衡 净初级生产力 净生态系统生产力 土地利用 施肥 

分 类 号：S154.4[农业科学—土壤学]