不同刈割频次对呼伦贝尔羊草草原土壤碳氮变化的影响  

Effects of different mowing frequencies on soil carbon and nitrogen changes in Leymus chinensis Steppe of Hulun Buir

作　　者：郝广 闫勇智 李阳[1] 李传弘 王炜琛 郭宇 杨九艳 HAO Guang;YAN Yongzhi;LI Yang;LI Chuanhong;WANG Weichen;GUO Yu;YANG Jiuyan(College of Life Sciences, Inner Mongolia University, Hohhot 010021, China;School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China)

机构地区：[1]内蒙古大学生命科学学院,呼和浩特010021 [2]内蒙古大学生态与环境学院,呼和浩特010021

出　　处：《应用与环境生物学报》2018年第2期195-199,共5页Chinese Journal of Applied and Environmental Biology

基　　金：内蒙古自然科学基金重大项目(2014ZD02)资助~~

摘　　要：刈割是内蒙古呼伦贝尔草原主要的管理方式，为向内蒙古地区碳汇管理提供理论依据，对围封样地、两年一割样地与一年一割样地的刈割频次与土壤碳氮含量关系开展研究. 结果显示，随刈割频次的增加，0-30 cm土层中土壤有机碳和全氮含量均表现出下降趋势，各土层中响应有所不同，表现为随土层深度加深，在围封样地和两年一割样地中逐渐减少，而在一年一割样地中逐渐增加. 土壤碳贮量、氮贮量存在显著的相关关系，且随刈割频次增加呈显著线性下降，碳氮固持潜力下降，表现为碳流失、氮流失. 其中两年一割样地土壤碳贮量下降17.1%、氮贮量下降20.8%，一年一割样地土壤碳贮量下降21.6%、氮贮量下降29.3%. 上述结果表明，呼伦贝尔羊草草原土壤碳氮变化对刈割频次较为敏感，合理控制刈割频次能够减缓碳氮流失，同时配合适当的施肥可实现草原的可持续利用. （图4 表1 参21）Mowing is the main management of Hulun Buir grasslands in Inner Mongolia; therefore, understanding the changes of soil organic carbon （SOC）, total nitrogen （TN）, and carbon sequestration under different mowing frequencies will provide an important scientific basis for grassland carbon sink management in Inner Mongolia. Three treatment plots were devised in the study area, including enclosed sample （Y）, mowing every other year （2G）, and mowing once a year （1G）, where SOC, TN content and storage were investigated. The results showed that with increased mowing frequency, the SOC and TN content showed a decreasing trend in the 0–30 cm depth soil layer. The SOC and TN content were different in each soil layer, which decreased gradually with increasing soil depth in Y and 2G plots, whereas increased gradually in 1G plots. The soil carbon storage was significantly correlated with the soil nitrogen storage, and both showed a significant linear decrease with increased mowing frequency, which showed as carbon and nitrogen loss. In 2G plots, the soil carbon storage decreased by 17.1% and soil nitrogen storage decreased by 20.8%. In 1G plots, the soil carbon storage decreased by 21.6% and soil nitrogen storage decreased by 29.3%. The results showed that the change of soil carbon and nitrogen was sensitive to mowing frequency for the Hulun Buir grassland. It is possible to reduce the loss of carbon and nitrogen by reasonably controlling mowing frequency, and the sustainable use of grassland could be achieved with appropriate fertilization.

关 键 词：刈割 羊草草原 土壤有机碳 土壤碳贮量 土壤氮贮量 

分 类 号：S812.2[农业科学—草业科学]