多年生高寒栽培草地土壤微生物学特性对短期氮添加的响应  

Response of Microbiological Properties to Short-term Nitrogen Addition in Perennial Alpine Cultivated Grassland

作　　者：童永尚 张春平 俞旸[1,2,3] 曹铨 杨增增 张小芳 王敏 董全民 TONG Yong-shang;ZHANG Chun-ping;YU Yang;CAO Quan;YANG Zeng-zeng;ZHANG Xiao-fang;WANG Min;DONG Quan-min(Qinghai Academy of Animal Science and Veterinary,Academy of Animal Science and Veterinary,Qinghai University,Xining 810016,China;Qinghai Provincial Key Laboratory of Adaptive Management on Alpine Grassland,Xining 810016,China;Key Laboratory of the Alpine Grassland Ecology in the Three Rivers Region,Ministry of Education,Qinghai University,Xining 810016,China;School of Geography and Environmental Science,Northwest Normal University,Lanzhou 730070,China)

机构地区：[1]青海大学畜牧兽医科学院,青海省畜牧兽医科学院,西宁810016 [2]青海省高寒草地适应性管理重点实验室,西宁810016 [3]青海大学三江源区高寒草地生态教育部重点实验室,西宁810016 [4]西北师范大学地理与环境科学学院,兰州730070

出　　处：《环境科学》2024年第12期7316-7325,共10页Environmental Science

基　　金：青海省重点研发与转化计划项目(2022-NK-134);国家重点研发计划项目(2022YFD1302104)。

摘　　要：解除氮限制是提高高寒草地植物生产力的必要措施.为了解氮添加对环青海湖地区多年生高寒栽培草地土壤理化性质和微生物群落结构的影响,进行了短期氮添加试验.于2022年6~8月,以4龄多年生栽培草地为研究对象,设置4个施氮梯度(T0:0kg·hm^(-2)·a^(-1),T1:22.5 kg·hm^(-2)·a^(-1),T2:45 kg·hm^(-2)·a^(-1),T3:67.5 kg·hm^(-2)·a^(-1)),采集0~20 cm土层的土壤样品,对不同处理下土壤理化性质和微生物群落结构进行了测定.结果表明,随着施氮水平的提高,土壤含水量(SWC)、有机碳(SOC)、铵态氮(NH_(4)^(+)-N)、硝态氮(NO_(3)^(-)-N)、速效氮(AN)、速效磷(AP)、全磷(TP)、全氮(TN)和全碳(TC)的含量均有增加趋势,T3处理显著降低了土壤pH.氮添加未显著改变土壤微生物群落的Alpha多样性,不同施氮水平对土壤微生物群落结构产生不同程度的影响.T1和T2处理增加了土壤细菌和真菌的数量,T3处理降低了土壤细菌和真菌的数量.氮添加提高了放线菌门、接合菌门、芽球菌属和赤霉菌属等优势菌群的相对丰度,降低了变形杆菌门、拟杆菌门、鞘氨醇单胞菌属和近明球囊霉属等优势菌群的相对丰度.RDA分析表明,SOC和土壤电导率(EC)是影响土壤细菌群落变化的关键土壤理化因子,土壤p H是影响土壤真菌群落分布的主要因素.综合而言,67.5kg·hm^(-2)·a^(-1)可能是改善多年生高寒栽培草地土壤环境的最佳施氮水平.Removing nitrogen limitation is necessary to increase plant productivity in alpine grasslands.A short-term nitrogen addition experiment was conducted to understand the effects of nitrogen addition on the soil physicochemical properties and microbial community structure of perennial alpine cultivated grassland in the region around Qinghai Lake.From June to August 2022,four N application gradients(T0:0 kg·hm^(-2)·a^(-1),T1:22.5 kg·hm^(-2)·a^(-1),T2:45 kg·hm^(-2)·a^(-1),T3:67.5 kg·hm^(-2)·a^(-1))were set up in a four-age perennial cultivated grassland,and soil samples were collected from the 0-20 cm soil layer.The soil physical and chemical properties and microbial community structure were determined under the different treatments.The results showed that soil water content(SWC),soil organic carbon(SOC),ammonium nitrogen(NH_(4)^(+)-N),nitrate nitrogen(NO_(3)^(-)-N),available nitrogen(AN),available phosphorus(AP),total phosphorus(TP),total nitrogen(TN),and total carbon(TC)tended to increase with the increase in nitrogen application level and the T3 treatment significantly decreased the soil pH.Nitrogen addition did not significantly alter the Alpha diversity of soil microbial communities and different levels of nitrogen application affected the structure of soil microbial communities to different degrees.The T1 and T2 treatments increased the number of soil bacteria and fungi and T3 treatment decreased the number of soil bacteria and fungi.Nitrogen addition increased the relative abundance of the dominant flora of Actinobacteriota,Zygomycota,Blastococcus,and Gibberella and decreased the relative abundance of the dominant flora of Proteobacteria,Bacteroidota,Sphingomonas,and Claroideoglomus.RDA analysis showed that SOC and soil electrical conductivity(EC)were the key soil physicochemical factors affecting changes in soil bacterial communities,and soil pH was the main factor affecting the distribution of soil fungal communities.Collectively,67.5 kg·hm^(-2)·a^(-1) may be the optimal level of N application to im

关 键 词：高寒栽培草地 施氮水平 土壤理化性质 微生物群落结构 冗余分析(RDA) 

分 类 号：X172[环境科学与工程—环境科学]