渭北旱塬不同年限撂荒地土壤酶活性及其化学计量变化特征  

Characteristics of Changes in Soil Enzyme Activities and Stoichiometric Under Different Abandoned Years in the Dry Area of Northern Weihe River Basin

作　　者：雷跻初 刘小伟 邓军 程杰 程积民[6] 郭梁 Lei Jichu;Liu Xiaowei;Deng Jun;Cheng Jie;Cheng Jimin;Guo Liang(Research Center for Soil and Water Conservation and Ecological Environment,Chinese Academy of Sciences and Ministry of Education,Yangling,Shaanxi 712100,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Grassland Agriculture,Northwest A&F University,Yangling,Shaanxi 712100,China;Administration Bureau of Ningxia Yunwushan National Nature Reserve,Guyuan,Ningxia 756000,China;Northwest Surveying Planning and Designing Institute of National Forestry and Grassland Administration,Xi′an 710048,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A&F University,Yangling,Shaanxi 712100,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences&Ministry of Water Resources,Yangling,Shaanxi 712100,China)

机构地区：[1]中国科学院教育部水土保持与生态环境研究中心,陕西杨凌712100 [2]中国科学院大学,北京100049 [3]西北农林科技大学草业与草原学院,陕西杨凌712100 [4]宁夏云雾山国家级自然保护区管理局,宁夏固原756000 [5]国家林业和草原局西北调查规划设计院,陕西西安710048 [6]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [7]中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《水土保持研究》2024年第1期44-52,共9页Research of Soil and Water Conservation

基　　金：国家自然科学基金(41701606);陕西省自然科学基础研究计划(2021JM-093);中央高校基本科研业务费(2452020009)资助。

摘　　要：[目的]探究渭北旱塬区不同年限撂荒地的土壤养分、胞外酶活性及其化学计量的变化特征及影响因素,以期为渭北旱塬区撂荒地的改善与管理提供一定的理论依据。[方法]以渭北旱塬不同年限(5 a, 10 a, 20 a, 25 a和33 a)的撂荒地为研究对象,测定了土壤养分和参与土壤碳(C)、氮(N)和磷(P)循环的5种胞外酶活性,随后利用单因素方差分析、土壤胞外酶化学计量学模型和主坐标分析(PCoA)研究不同撂荒年限下土壤养分和胞外酶活性及其生态化学计量的变化规律及影响因子。[结果]随着撂荒年限的增加,土壤C和N获取酶活性显著减小,而P获取酶活性显著增加;土壤C、N和P含量变化与酶活性变化趋势相反。随撂荒年限延长,土壤微生物的C限制得到缓解,P限制逐渐加强。PCoA拟合环境因子分析结果显示:土壤可溶性有机碳(DOC)、总磷(TP)、速效氮(AN)和速效磷(AP)含量是驱动酶活性及其计量比变化的关键因子。[结论]撂荒对土壤养分状况具有显著改善作用,但随撂荒时间延长(20 a以上)会加剧微生物P限制,因此对经过长年撂荒的土地应当适量施用磷肥,以改善其土壤状况。[Objective]This study aims to explore the variations and drivers of soil nutrient and extracellular enzyme activities and their stoichiometric characteristics under the abandoned land in the dry area of Northern Weihe River Basin in order to provide a theoretical basis for the improvement and management of abandoned land in this region.[Methods]Soil nutrients and enzyme activities associated with carbon(C),nitrogen(N),and phosphorus(P)cycles in the lands with different abandoned years(5 years,10 years,20 years,25 years and 33 years)in dry area of Northern Weihe River Basin were measured.Subsequently,The changes and driver factors of them and their stoichiometry were determined by One-way ANOVA,enzyme stoichiometric model,and principal coordinate analysis(PCoA).[Results]With the increase of abandoned years,the activities of C-acquiring enzymes and N-acquiring enzymes decreased,but the activity of P-acquiring enzymes significantly increased.The changes of soil C,N and P contents showed the opposite trend compared with enzyme activities.Moreover,the C-limitation of soil microorganisms alleviated but P-limitation increased with the increase of abandoned years.Further,the results of PCoA fitting environmental factor analysis showed that soil dissolved organic carbon,total phosphorus,available nitrogen and available phosphorus were the key factors driving the change of enzyme activity and its econometric ratio.[Conclusion]Abandonment has a significant improvement on soil nutrient,but P-limited will be aggravated with increasing of abandoned years(more than 20 years).Therefore,appropriate phosphate fertilizer should be applied to a long-term abandoned land to improve its soil condition.

关 键 词：渭北旱塬 不同撂荒年限 土壤酶活性 生态化学计量 

分 类 号：X144[环境科学与工程—环境科学]