施肥和刈割5年对呼伦贝尔草甸草原土壤微生物特征的影响  

Effects of fertilization and mowing for 5 years on soil microbial characteristics in Hulunbuir meadow steppe

作　　者：马远飞 宋彦涛 乌云娜 方乘风 MA Yuan-fei;SONG Yan-tao;WU Yun-na;FANG Cheng-feng(College of Environment and Bioresources,Dalian Minzu University,Dalian 116600,China)

机构地区：[1]大连民族大学环境与资源学院,辽宁大连116600

出　　处：《草业学报》2024年第9期242-251,共10页Acta Prataculturae Sinica

基　　金：国家自然科学基金项目(32171556);国家民委中青年英才培养计划项目(2022);中央高校基本科研业务费(2024)资助。

摘　　要：土壤微生物在维持草原生态系统功能方面发挥重要的作用,合理的利用和管理有助于维持草原资源可持续利用。为探究草甸草原土壤微生物对于不同施肥和留茬高度处理的适应性,在呼伦贝尔草甸草原进行了为期5年的野外控制试验,包括2个施肥水平:施肥(F)、不施肥(NF),6个刈割留茬高度:3、6、9、12、15 cm和不刈割(CK),两因子交互共12个处理,测定土壤磷脂脂肪酸(phospholipid fatty acid,PLFA)含量及理化性质。结果表明:不施肥处理下,随着刈割留茬高度的增加,土壤微生物生物量在9 cm时最高,然后趋于平稳;施肥处理下,微生物生物量在不同留茬高度间无明显差异。留茬高度不高于9 cm时,施肥能够提高微生物生物量,补偿低留茬刈割引起的微生物生物量下降,留茬高度高于9 cm时,施肥抑制刈割引起的微生物生物量升高;施肥显著提升了微生物群落中放线菌的相对丰度与群落相异度指数;硝态氮是影响土壤微生物群落组成的主要环境因子。本研究表明呼伦贝尔草甸草原土壤微生物对于刈割留茬高度9 cm的适应性最好,更低的留茬高度则需要通过施肥来补充供给微生物所需的土壤养分,缓解生物量的下降。这些发现为草原资源的可持续利用和生态保护提供了参考依据。Soil microorganisms play an important role in sustaining the functionality of grassland ecosystems,and their rational utilization and management contributes to the sustainable exploitation of grassland resources.The aim of this study was to investigate the adaptability of soil microorganisms to different fertilization and mowing stubble height treatments in a meadow steppe,and a five-year,controlled field experiment was conducted in Hulunbuir,China.This experiment included fertilization(F)and no fertilization(NF)treatments,along with six mowing treatments:stubble heights of 3,6,9,12,15 cm,and no mowing(CK).These two factors were combined factorially to form a total of 12 treatments,and soil phospholipid fatty acids(PLFA)and soil physicochemical properties were determined.It was found that,compared to the NF treatments,with increase in stubble height,soil microbial biomass peaked at 9 cm and then stabilized.Under the F treatment,microbial biomass showed no significant differences among stubble heights.Up to a stubble height of 9 cm,fertilization enhanced microbial biomass,compensating for the reduction caused by low stubble height.However,for stubble heights exceeding 9 cm,fertilization suppressed the microbial biomass increase associated with mowing.Fertilization significantly increased the relative abundance of Actinomycetes in the microbial community and the index of community dissimilarity.Nitrate-nitrogen emerged as the primary environmental factor influencing the composition of the soil microbial community.This study indicated that soil microorganisms exhibit optimal adaptability at a mowing stubble height of 9 cm in Hulunbuir meadow steppe.For stubble heights lower than 9 cm,fertilization was needed to supplement soil nutrients for microorganisms and mitigate biomass decline.These findings provide scientific data to facilitate the design of management systems for the sustainable utilization and ecological protection of grassland resources.

关 键 词：施肥 刈割 留茬高度 土壤微生物 PLFA 

分 类 号：S812.2[农业科学—草业科学]