荒漠草原优势植物细根分解对土壤碳矿化与土壤养分的影响  

Effects of dominant plant fine roots decomposition on soil carbon mineralization and soil nutrients in desert steppe

作　　者：敖道 何嘉 郭文龙 白皓天 张建军[1] 杨鑫 AO Dao;HE Jia;GUO Wen-long;BAI Hao-tian;ZHANG Jian-jun;YANG Xin(College of Forestry and Prataculture,Ningxia University,Yinchuan 750021,China;Ningxia Grassland and Animal Husbandry Engineering Technology Research Center,Yinchuan 750021,China)

机构地区：[1]宁夏大学林业与草业学院,银川750021 [2]宁夏草牧业工程研究中心,银川750021

出　　处：《西南农业学报》2024年第5期1063-1070,共8页Southwest China Journal of Agricultural Sciences

基　　金：宁夏自然科学基金优秀青年项目(2023AAC05012);中国科学院“西部之光”青年学者项目(XAB2022YW15);宁夏高等学校一流学科建设(草学学科)项目(NXYLXK2017A01)。

摘　　要：【目的】研究宁夏东部荒漠草原优势植物细根分解对土壤碳矿化与土壤养分的影响,进一步分析优势植物细根分解动态与养分返还过程。【方法】以宁夏东部荒漠草原优势植物短花针茅(Stipa breviflora)与蒙古冰草(Agropyron mongolicum)细根为研究对象,设置对照(CK)、添加短花针茅细根(Sb)与添加蒙古冰草细根(Am)3种处理,采用室内培养法研究细根分解特征及其对土壤碳矿化与土壤养分的影响。【结果】连续培养61 d后,添加短花针茅和蒙古冰草细根显著增加土壤24 h CO_(2)释放总量、分解初期(前14 d)土壤碳矿化速率与累积CO_(2)释放量(P<0.01)。添加短花针茅与蒙古冰草细根使土壤激发效应显著增加(P<0.01),增幅为40.50%与35.28%。与CK相比,添加短花针茅和蒙古冰草细根显著增加土壤硝态氮含量(P<0.01),对土壤速效磷无显著影响。细根纤维素含量、m(C)∶m(N)与24 h CO_(2)释放总量呈显著负相关(P<0.05);细根碳含量、木质素含量、m(木质素):m(N)与24 h CO_(2)释放总量呈显著正相关(P<0.05)。细根木质素含量、m(木质素)∶m(N)与累积CO_(2)释放量呈显著正相关(P<0.05)。细根碳含量、氮含量、纤维素含量、m(N)∶m(P)与细根损失率呈显著正相关;细根木质素含量、m(木质素)∶m(N)与细根损失率呈显著负相关。【结论】植物细根初始化学性质是影响荒漠草原土壤有机碳矿化与养分循环的重要因素之一。[Objective]The study aimed to analyze the effect of dominant plant fine root decomposition on soil carbon mineralization and soil nutrients to further reveal the underground ecological processes in desert steppe.[Method]Fine roots of Stipa breviflora and Agropyron mongo-licum were selected in the study.There were three treatments including control(CK),S.breviflora(Sb)and A.mongolicum(Am).An incu-bate method was used to test the effects of fine roots decomposition on soil carbon mineralization and soil nutrients.[Result]S.brevifloris and A.mongolicum fine roots additions significantly increased 24-hour CO_(2) reflux,the soil carbon mineralization rate at the initial decomposition stage(first 14 days),and cumulative CO_(2) reflux(P<0.01).Fine roots additions increased the soil priming effects by 40.50%and 35.28%,respectively(P<0.01).S.brevifloris and A.mongolicum fine roots inputs significantly increased soil NO;-N content(P<0.01),but had no significant effect on soil available P content.cellulose content and m(C):m(N)of fine root were negatively correlated with 24-hour CO_(2) reflux(P<0.05).The carbon content,lignin content and m(lignin):m(N)in fine root were positively correlated with 24-hour CO_(2) reflux(P<0.05).The lignin content and m(lignin):m(N)of fine roots were positively correlated with the cumulative CO_(2) release(P<0.05).Fine root carbon content,N content,cellulose content and m(N):m(P)were positively correlated with the fine root loss ratio;The lignin content,m(lignih):m(N)of fine roots were negatively correlated with the loss ratio of fine roots.[Conclusion]The initial chemical properties of plant fine roots are one of the important factors changing the decomposition and nutrient cycling of fine roots in desert steppe.

关 键 词：根系 土壤养分 碳矿化 荒漠草原 

分 类 号：S151.9[农业科学—土壤学]