摘要
以建于1990年的新疆阜康荒漠生态系统观测研究站的长期施肥定位试验为平台,分析了不施肥(CK)、单施化肥(化肥常规NPK和化肥高量N2P2K)、化肥配施秸秆(化肥配施秸秆常规NPKS和化肥配施秸秆高量NPKS2)和化肥配施猪粪(NPKM)对农田土壤有机碳和无机碳含量与剖面分布及有机碳热稳定性的影响。结果表明:(1)长期施肥处理提高了土壤有机碳含量,其中耕层(0—20 cm)土壤有机碳响应最敏感,化肥配施秸秆还田处理下有机碳积累高于其他处理。(2)长期施肥处理均降低土壤有机碳稳定性,表明增加的土壤有机碳并不利于碳稳定。(3)长期施肥处理降低土壤无机碳含量,其降低程度随剖面呈下降趋势,可能由于灌溉淋洗导致深层土壤无机碳的净增加。(4)尽管长期施肥促进土壤有机碳累积,但由于降低无机碳含量及其储量,最终导致土壤全碳降低,表明土壤无机碳变化对干旱区土壤碳库变化具有决定性作用。结果表明,深入理解施肥措施对干旱区盐碱土的碳影响,需要同时考虑不同深度土壤有机碳和无机碳含量的变化。
The croplands in arid regions are characterized by saline-sodic soils,low content of soil organic carbon(SOC),and large proportions of soil inorganic carbon(SIC).Both SOC and SIC are influenced by agricultural management.However,it remains unclear that how the stock and stability of SOC and SIC at different soil depths vary after long-term fertilizations.We investigated the vertical patterns of soil carbon(C)change and SOC stability in six fertilization treatments(e.g.,CK,NPK,N2P2K,NPKS,NPKS2,and NPKM)in the Fukang Station for Desert Ecological Research,Chinese Academy Sciences.The results showed that:(1)The contents and stocks of SOC in the tilled layer(0—20 cm)increased after 31-year fertilizations,especially in the treatment of chemical fertilizer combined with straw returning,which could be due to high plant C inputs.(2)In addition,the thermal stability of SOC decreased in all the fertilization treatments,suggesting that increased SOC after long-term fertilizations might be vulnerable to environmental changes and would promote the transformation of soil nutrients.(3)The contents and stocks of SIC decreased in different fertilization treatments,and the decreases in SIC reduced along soil profiles,resulting in the increment of SIC to the depth of 60 cm,which might be caused by irrigation.(4)Despite the increases in SOC after the long-term fertilizations,the decreases in SIC led to the loss of soil total C,demonstrating that the changes in SIC determine the net changes in soil C in the arid regions.Overall,the results of this study suggest to estimate accurately the changes in soil C in the arid regions,we need to understand changes in both SOC and SIC and their stabilities at different soil depths.
作者
向姣
王著峰
王玉刚
冯文婷
XIANG Jiao;WANG Zhufeng;WANG Yugang;FENG Wenting(State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011;National Fukang Desert Ecosystem Field Science Observation and Research Station, Chinese Academy of Sciences, Fukang, Xinjiang 831505;University of Chinese Academy of Sciences, Beijing 100049;Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081)
出处
《水土保持学报》
CSCD
北大核心
2022年第4期333-341,共9页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(42077023,U1803342)
国家重点研发计划项目“政府间重点专项”(YS2020YFE010321)。
关键词
长期试验
秸秆还田
土壤剖面
盐碱土
无机碳
有机碳稳定性
热学分析
long-term experiment
straw returning
soil depth
saline-sodic soil
inorganic carbon
soil organic carbon stability
thermal analysis