氮添加对草地生态系统土壤pH、磷含量和磷酸酶活性的影响  

Effect of nitrogen additions on soil pH,phosphorus contents and phosphatase activities in grassland

作　　者：田沐雨 于春甲 汪景宽[1] 丁凡[1] 陈振华[3] 姜楠 蒋晖 陈利军[3] TIAN Mu-yu;YU Chun-jia;WANG Jing-kuan;DING Fan;CHEN Zhen-hua;JIANG Nan;JIANG Hui;CHEN Li-jun(College of Land and Environment,Shenyang Agricul-tural University,Shenyang 110866,China;School of Environment,Liaoning University,Shenyang 110036,China;Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China;Dalian Center for Certification and Food and Drug Control,Dalian 116037,Liaoning,China)

机构地区：[1]沈阳农业大学土地与环境学院,沈阳110866 [2]辽宁大学环境学院,沈阳110036 [3]中国科学院沈阳应用生态研究所,沈阳110016 [4]大连市检验检测认证技术服务中心,辽宁大连116037

出　　处：《应用生态学报》2020年第9期2985-2992,共8页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41877108);国家重点研发专项(2016YFD0300802)资助。

摘　　要：磷是植物必需的大量营养元素之一,也是草地生态系统功能的重要限制因子。近年来,随着全球氮沉降的迅速增加,草地生态系统土壤磷及磷酸酶活性受到不同程度的影响。本研究采用整合分析方法,分析了草地的氮添加量、氮源种类、持续时间和土层深度等对土壤pH、全磷(TP)含量、有效磷(AP)含量、碱性磷酸酶(AlP)和酸性磷酸酶(AcP)活性的影响,以及土壤pH与磷酸酶活性的相关性。结果表明:氮添加降低了土壤pH、TP含量和AlP活性,提高了土壤AcP活性,但对土壤AP含量无显著影响。从氮添加量来看,土壤pH、AlP显著降低在氮添加>5 g·m^(-2)·a^-1条件下即可发生;高水平氮添加(>10 g·m^(-2)·a^-1)导致AcP活性显著提高;土壤TP、AP含量显著降低仅发生在氮添加量为5~10 g·m^(-2)·a^-1条件下。硝酸铵处理显著降低了土壤TP含量,提高了AcP活性;尿素处理显著降低了土壤pH和AlP活性。在所有添加量下,当试验持续时间为3~10年时,土壤TP含量、AlP活性显著降低;持续时间大于3年时,土壤pH显著降低;>10年时,AcP活性显著提高。0~10 cm土层的AP含量显著升高,TP含量和AlP活性显著降低;大于10 cm土层中AP含量显著降低。土壤pH与土壤AcP活性呈显著负相关,表明氮添加引起的土壤pH改变可能是土壤磷酸酶活性变化的重要原因。Phosphorus is a key nutrient for all plant species and a limiting factor for grassland ecosystem function.In recent years,in response to the rapid increase of global nitrogen deposition,soil phosphorus contents and phosphatase activities changed to varying degrees in grassland ecosystems.We conducted a meta-analysis to examine the responses of soil pH,total phosphorus(TP),available phosphorus(AP),as well as activities of alkaline phosphatase(AlP)and acid phosphatase(AcP)in soils to nitrogen addition amount,nitrogen type,experimental duration,and sampling depth.The correlation between soil pH and phosphatase response ratio was investigated.The results showed that nitrogen addition significantly reduced soil pH,TP and AlP activity,while significantly increased AcP activity,but had no significant effect on AP.Soil pH and AlP activity significantly decreased under nitrogen addition>5 g·m-2·a-1,and AcP activity significantly increased under high nitrogen addition(>10 g·m-2·a-1).The contents of TP and AP significantly decreased when nitrogen addition was 5-10 g·m-2·a-1.NH4NO3 treatment significantly reduced soil TP and increased AcP activity,while urea treatment significantly reduced soil pH and AlP activity.Across all nitrogen addition amounts,when the experiment duration was 3 to 10 years,soil TP content and AlP activity were significantly reduced.Soil pH was significantly reduced after three years nitrogen addition,and AcP activitiy was significantly increased after 10 years nitrogen addition.In the 0-10 cm soil layer,the TP content and AlP activity significantly decreased,while the AP content significantly increased.In>10 cm soil layer,the AP content was significantly decreased.The significant negative correlation between soil pH and AcP activity indicated that change in soil pH caused by nitrogen addition may be an important factor for the variation of soil phosphatase activity.

关 键 词：草地 氮添加 土壤PH 土壤磷 土壤磷酸酶 整合分析 

分 类 号：S812[农业科学—草业科学]