渭北塬区不同龄苹果园土壤微生物空间分布特征  

Spatial distribution of soil microorganisms in apple orchards of different ages on the Weibei rainfed tableland of the Loess Plateau,China

作　　者：甘卓亭[1,2] 张蓓蓓[1,2] 张掌权[1] 周旗[1,2] 郑晖[1,2] 

机构地区：[1]宝鸡文理学院,陕西省灾害监测与机理模拟重点实验室,宝鸡721013 [2]宝鸡文理学院,渭河流域资源环境与生态文明研究所,宝鸡721013

出　　处：《生态学报》2015年第21期6965-6973,共9页Acta Ecologica Sinica

基　　金：国家“十一五”科技支撑计划资助项目(2006BAD09B09);陕西省教育厅自然科学专项(2010JK402);宝鸡文理学院重点项目(ZK1041,ZK0846)!

摘　　要：以渭北塬区塬面5、10、15和20龄苹果园为对象,距树干1.0、1.5、2.0 m处用土钻法分层采集0—30 cm土样,稀释平板法测定土壤微生物数量,平行测定土壤有机碳、总氮和总磷,分析不同龄果园土壤微生物的空间分布状况及其与土壤碳、氮、磷的关系。结果表明:土壤真菌数量随树龄增大而增加,龄间差异显著(P<0.05);与对照农田相比,各龄果园放线菌数量及5龄和20龄果园细菌数量偏低,10龄和15龄果园细菌数量偏高;各龄果园土壤真菌、细菌和放线菌数量均随深度增加而减小。就相同深度土层而言,真菌数量随果园年限增大而增加,细菌则以10龄和15龄果园较多,同深度土层的放线菌龄间差异随深度增加而减小。在沿树干向外的径向水平方向上,真菌数量随果园年限的增加相应增多;10龄和15龄果园土壤细菌和放线菌高于5龄果园和20龄果园。5龄果园土壤总氮有沿树干向外、沿表层向下逐步降低的趋势,果园从5龄经10龄到15龄,其"高氮点"则逐步向外、向下移动。塬区果园土壤C∶N比偏低。Soil microorganisms are vital for orchard ecosystems, as they determine and promote the material cycle and energy flow. The Weibei Loess Plateau is one of the main regions producing high-quality apples since the 1980s. The planting structure of apple orchards has following characteristics： simple and long-term fertilizer, high quality management, and ＂double high＂ （high investment and high harvest） production, which results in diiferent soil fertility and quality in orchards of different ages, leading to different habitat conditions for microorganisms. Consequently, different aged orchards have different soil microbial species composition, quality, and spatial distributions. Yet, differences in soil microorganism parameters affect apple yield and quality, because of their involvement in maintaining and improving the feedback effect on s0il properties and fertility in orchards. To maintain sustainable development, prevent soil quality degradation, and reform orchard degradation, it is essential to understand the long-term dynamics and trends of microorganisms in orchards. This work investigated the spatial distribution of soil microorganisms in different apple orchards of different ages （5, 10, 15, and 20 years old） on the Weibei rainfed tableland of the Loess Plateau. Soil samples were first collected from the 0---30cm soil layer at root radial distances of 1.0, 1.5, and 2.0 m away from the main tree trunk using a soil coring method. Soil total nitrogen （TN）, soil total phosphorus （TP）, and soil organic carbon （SOC） were then determined using the Flowsys III and Liqui TOC II analyzer. Relationships between soil microorganisms and soil nutrients （i.e., TN, TP, and SOC） were also analyzed. The results showed that the soil fungal population increased with increasing apple orchard age. There were significant differences in soil fungal population among orchard ages, at the P=0.05 level. The soil actinomycete population in orchards of all ages and soil bacterial population in 5-year and 20

关 键 词：土壤微生物 空间分布 渭北旱塬 

分 类 号：S661.1[农业科学—果树学] S154.3[农业科学—园艺学]