氮添加对青藏高原高寒草甸土壤磷组分的影响  

Effects of Nitrogen Addition on Soil Phosphorus Fractions in an Alpine Meadow of Qinghai-Tibet Plateau

作　　者：韩冰[1] 耿依仪 邓艳芳 王宇飞 周华坤[3] 邵新庆[1] 李芝雯 HAN Bing;GENG Yi-yi;DENG Yan-fang;WANG Yu-fei;ZHOU Hua-kun;SHAO Xin-qing;LI Zhi-wen(College of Grassland Science and Technology,China Agricultural University,Beijing 100193,China;Qilian Mountain National Park Qinghai Service Guarantee Center,Xining,Qinghai Province 810000,China;Northwest Institute of Plateau Biology,Chinese Academy of Science,Key Laboratory of Restoration Ecology of Cold Area in Qinghai Province,Xining,Qinghai Province 810001,China;Agriculture and Animal Husbandry Bureau of Qilian County in Qinghai Province,Xining,Qinghai Province 810400,China)

机构地区：[1]中国农业大学草业科学与技术学院,北京100193 [2]祁连山国家公园青海服务保障中心,青海西宁810000 [3]中国科学院西北高原生物研究所,青海省寒区恢复生态学重点实验室,青海西宁810001 [4]青海省祁连县农牧水利科技和乡村振兴局,青海西宁810400

出　　处：《草地学报》2022年第10期2721-2728,共8页Acta Agrestia Sinica

基　　金：青海省科技厅创新平台建设专项(2020-ZJ-T07)项目资助。

摘　　要：磷是一种影响草地植物生产力和生态系统功能的重要养分。本文研究了3个氮添加水平下(5,10和15 g·m^(-2))青藏高原海北高寒草甸(海拔3100 m)土壤磷组分的变化特征及其主要影响因素。研究表明:N5处理下土壤磷的生物有效性增加。N5处理显著提高了活性磷库的含量,其中NaHCO_(3)-Pi的含量和比例均显著增加。N15处理下植物生物量和地上部含磷量增加,土壤活性磷含量无显著变化,N15处理下仅土壤残余态磷(Residual-P)显著下降。氮添加下影响土壤磷组分变化的关键因素包括土壤pH值、微生物生物量碳(Microbial biomass carbon,MBC)和微生物生物量氮(Microbial biomass nitrogen,MBN)。在高寒草甸氮添加能够通过降低土壤pH值和增加微生物生物量来提高土壤磷的有效性。Phosphorus(P)is an essential nutrient that affects plant productivity and ecosystem function in grasslands.In this study,we investigated the responses of soil P fractions to different levels of nitrogen(N)addition(5,10 and 15 g·m^(-2) for N5,N10,and N15 respectively)and the mechanisms in an alpine meadow of Haibei,Qinghai-Tibet Plateau(3100 m).We found that low N addition could improve the availability of soil P,as N5 treatment significantly increased the content of the labile P pool,as well as the content of NaHCO_(3)-Pi.In contrast,high N addition increased the aboveground biomass and P content in plant shoots,but no significant changes of labile P pool in the soil.Actually,only soil residual-P was significantly decreased under N15 treatment.The further analysis revealed key factors which might affect soil P fractions under N addition,including soil pH,microbial biomass carbon(MBC),and microbial biomass nitrogen(MBN).In conclusion,N additions increased the soil P availability,due to decreased soil pH and increased microbial biomass content in alpine meadows.

关 键 词：土壤磷库 Hedley磷连续提取法 土壤生物和非生物特性 植物生物量 

分 类 号：S153.6[农业科学—土壤学]