长期施肥下旱地红壤不同保护态有机碳库变化特征  

Variation characteristics of organic carbon pools with different protection methods in upland red soil under long-term fertilization

作　　者：李文军 黄庆海[1] 李大明[1] 柳开楼[1] 张文菊[2] 徐明岗[2] LI Wenjun;HUANG Qinghai;LI Daming;LIU Kailou;ZHANG Wenju;XU Minggang(Jiangxi Key Laboratory of Arable Land Conservation of Red soil,Jiangxi Institute of Red Soil,Nanchang 330046,China;National Engineering Laboratory for Improving Quality of Arable Land,Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 100081,China;Hunan Province Cooperative Innovation Center for the Construction and Development of Dongting Lake Ecological Economic Zone,Hunan University of Arts and Science,Changde 415000,China)

机构地区：[1]江西省红壤研究所,江西省红壤耕地保育重点实验室,南昌330046 [2]中国农业科学院农业资源与农业区划研究所,耕地培育技术国家工程实验室,北京100081 [3]湖南文理学院,洞庭湖生态经济区建设与发展湖南省协同创新中心,湖南常德415000

出　　处：《农业资源与环境学报》2023年第1期106-115,共10页Journal of Agricultural Resources and Environment

基　　金：国家自然科学基金项目(41620104006);中国博士后科学基金项目(2018M642595);湖南省教育厅优秀青年科研项目(18B404);江西省红壤耕地保育重点实验室开放基金(2019-01)。

摘　　要：为研究长期施肥对旱地红壤不同保护态有机碳组分(库)的影响,在不施肥(CK)、单施氮肥(N)、施常量氮磷钾肥(NPK)、施2倍量氮磷钾肥(HNPK)、氮磷钾肥配施有机肥(NPKM)、单施有机肥(M)6个处理下,分析物理-化学联合分组方法分离的土壤未保护、物理保护、物理-化学保护、物理-生物化学保护、化学保护、生物化学保护的有机碳组分的含量特征及其与总有机碳含量的关系,并探究土壤各保护态有机碳库储量与累积碳投入量间的关系。结果表明,CK与N处理间的土壤各保护态有机碳组分的含量均无显著差异(P>0.05)。与CK相比,施氮磷钾肥(NPK、HNPK)与有机肥(M、NPKM)处理的土壤总有机碳含量、未保护有机碳组分含量、物理保护有机碳组分含量分别提高13.3%~48.0%、39.2%~221.5%、41.9%~132.3%,土壤未保护有机碳、物理保护有机碳占土壤总有机碳的比例提高1.9~10.0、2.5~5.5个百分点,增幅均达显著水平(P<0.05),该效应在施有机肥条件下表现更为明显。土壤各保护态有机碳组分含量与总有机碳含量均呈正相关关系,线性回归方程拟合结果显示,单位总有机碳含量增加引起的未保护游离粗颗粒有机碳和物理保护有机碳含量的变化值分别达44.3%和28.0%(P<0.001)。除土壤生物化学保护有机碳外,其他保护态有机碳库的储量均与累积碳投入量呈极显著线性正相关(P<0.01)。研究表明,施肥后土壤增加的有机碳优先固存于未保护游离粗颗粒有机碳和物理保护有机碳组分中。与施化肥相比,有机培肥可更好地促进旱地红壤总有机碳的固存、提升有机碳的活性及增强有机碳的物理保护作用。在当前碳投入水平下,旱地红壤的生物化学保护有机碳可能已接近平衡状态。This study aimed to understand the content changes of different protected soil organic carbon(SOC)fractions in upland red soil that have been affected by long-term fertilization management, and to explore the equilibrium or saturation for SOC pools with varying protection methods. Surface(0~20 cm)samples of upland red soil that were subjected to six different treatments were collected from a longterm fertilization experiment. Treatments included no fertilizer application(CK);chemical nitrogen fertilizer alone(N);conventional usage amount of chemical N, phosphorus(P), and potassium(K)fertilizers(NPK), double usage amount of chemical NPK fertilizers(HNPK),chemical NPK fertilizers plus organic manure(NPKM), and organic manure alone(M). The total organic carbon(TOC)of soil was then separated into six different functional pools by the recently developed physical-chemical fractionation method, which included unprotected SOC, physically protected SOC, physical-chemically protected SOC, physical-biochemically protected SOC, chemically protected SOC,and biochemically protected SOC pools. The responses of the contents of SOC fractions with varying protection mechanisms to long-term fertilization were assessed, and the relationships between the contents of different protected SOC fractions and TOC, as well as between storages of different protected SOC pools and accumulated C input were investigated. The results showed that there was no significant(P>0.05)difference in the contents of all the separated SOC fractions between CK and N treatments. The TOC content, the contents of unprotected SOC and physically protected SOC fractions in NPK, HNPK, M, and NPKM, however, were significantly increased by 13.3%–48.0%, 39.2%-221.5%, 41.9%-132.3% respectively, compared with CK treatment. The proportions of unprotected SOC and physically protected SOC in TOC were significantly(P<0.05)increased under all the fertilization treatments with an exception of N treatment by 1.9-10.0 and 2.5-5.5 percentage points respectively as compared wi

关 键 词：长期施肥 旱地 红壤 土壤有机碳 物理-化学联合分组 有机碳组分 

分 类 号：S153.6[农业科学—土壤学]