氮输入下湿地植物根际分泌物对氮矿化过程影响特征  

Influence characteristics of rhizosphere exudates of wetland plants on nitrogen mineralization under nitrogen input

作　　者：赵士喆 刘芬[1] 乔睿萱 尹涵宇 王惠翔 赵春宇 ZHAO Shizhe;LIU Fen;QIAO Ruixuan;YIN Hanyu;WANG Huixiang;ZHAO Chunyu(College of Ecology,Resources and Environment,Dezhou University,Dezhou,253023,China;Key Laboratory of Tropical Marine Bio-resources and Ecology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China)

机构地区：[1]德州学院,生态与资源环境学院,德州253023 [2]中国科学院南海海洋研究所,热带海洋生物资源与生态重点实验室,广州510301

出　　处：《生态科学》2024年第6期70-76,共7页Ecological Science

基　　金：山东省自然科学基金资助项目(ZR2020QC052);德州学院学科(平台)建设项目(2023XKZX030);山东省大学生创新创业训练计划(S202110448002);德州学院博士启动基金(2019xjrc338)。

摘　　要：为探讨不同形态的氮输入对湿地植物根际周围土壤有机氮矿化过程的影响机制,于2021年8月采集了德州减河湿地芦苇及原位土进行加富栽培实验,并利用连续淹水培养法进行氮矿化速率测定。结果表明:不同氮输入对植物根际分泌物的释放有不同影响,其中NH4-Cl和尿素的复合添加对于芦苇根际氨基酸、类黄酮、总酚和总糖含量的增加效果最明显(P<0.01),但对总酸类的分泌无显著影响。氮添加对脲酶活性有显著促进作用(P<0.01),脲酶活性介于88.90—500.00μg·g^(-1)·d^(-1)之间,而对蛋白酶活性的促进效果不显著。土壤氮的矿化速率在5.79—21.12 mg·kg^(-1)·d^(-1)之间,并与脲酶之间呈现出了显著的正相关关系(P<0.05),脲酶活性最高值出现在尿素添加组,对矿化过程起到重要调控作用。根际土壤中脲酶的活性与TOC和TN的含量呈显著正相关(P<0.01),高TOC含量为微生物新陈代谢提供的能量,促进了微生物代谢产物增加,而土壤中TN可以显著诱导脲酶的产生。除总酸物质外,其余根际分泌物与MBN、MBC和脲酶活性均呈显著正相关(P<0.05)。外源氮输入通过刺激植物分泌物的释放,改变根际周围土壤的微环境,为矿化微生物提供代谢所需的底物和能量,促进有机氮矿化过程的发生。因此,在湿地管理过程中要加强湿地植物的保护和修复,提高湿地的生态服务功能。To explore the role of different forms of N input on the process of organic N mineralization in rhizosphere soil of wetland plants,the rate of N mineralization was measured using the continuous flooding incubation method with the reeds and in-situ soils of Dezhou Jianhe wetland which was collected in August 2021.The results showed that there was different effect on the release of root exudates among different N treatment,where the addition of NH4-Cl and urea had the most obvious effect on the increase of amino acids,flavonoids,total phenols and total sugars contents in rhizosphere roots(P<0.01),but had no significant effect on the secretion of total acids.Nitrogen addition had a significant effect on urease activity(P<0.01),and the urease activity ranged from 88.90 to 500.00μg·g-1·d-1,but had no significant effect on protease activity.The mineralization rate of soil N ranged from 5.79 to 21.12 mg·kg^(-1)·d^(-1),which showed a significant positive correlation with urease(P<0.05),indicating that urease could play an important role in regulating the mineralization process.The activities of urease in the rhizosphere soil were significantly and positively correlated with the content of TOC and TN(P<0.01).The high TOC content provided energy for microbial metabolism and promoted the increase of microbial metabolites.TN could significantly induce the production of urease.Except for total acids,all root exudates showed significant positive correlations(P<0.05)with MBN,MBC and urease activities.The exogenous N input mainly promotes the mineralization process of organic N by stimulating the release of plant root exudates,changing the microenvironment of the soil around the roots,and provides the substrate and energy for mineralized microorganisms.Therefore,it is necessary to strengthen the protection and restoration of wetland plants and improve the ecological service function of wetland in the process of wetland management.

关 键 词：氮添加 根际分泌物 有机氮矿化 影响因素 湿地土壤 

分 类 号：X53[环境科学与工程—环境工程]