基于酶化学计量法探究有机无机肥配施调控果园土壤微生物碳、磷代谢机制  

Seasonal Regulation of Soil Microbial Carbon and Phosphorus Metabolisms in an Apple Orchard:Evidence from the Enzymatic Stoichiometry Method

作　　者：吕凤莲[1] 梁凯霖 吉冰洁 郑朝霞 赵志远[1,2] 李利敏[1] 李紫燕[1,2] 郑伟[1,2] 翟丙年[1,2] LÜFeng-lian;LIANG Kai-lin;JI Bing-jie;ZHENG Zhao-xia;ZHAO Zhi-yuan;LI Li-min;LI Zi-yan;ZHENG Wei;ZHAI Bing-nian(Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China,Ministry of Agriculture and Rural Affairs,College of Natural Resources and Environment,Northwest A&F University,Yangling 712100,China;Apple Experimental Station of Northwest A&F University,Baishui 715600,China)

机构地区：[1]西北农林科技大学资源环境学院,农业农村部西北植物营养与农业环境重点实验室,杨凌712100 [2]西北农林科技大学苹果试验站,白水715600

出　　处：《环境科学》2023年第10期5788-5799,共12页Environmental Science

基　　金：国家自然科学基金项目(42007093);陕西省科技重大专项(2020zdzx03-02-01);国家现代农业产业技术体系项目(CARS-27);中国博士后科学基金项目(2020M638585);陕西省自然科学基础研究计划项目(2022JQ-288)。

摘　　要：土壤微生物的C、N、P养分需求和代谢限制与环境养分的有效性有着密切关系.然而,有机无机肥配施如何影响苹果园土壤微生物C、N、P代谢限制亟待进一步研究.因此,基于2008年建立的苹果园长期定位试验,应用土壤酶化学计量学理论与方法,系统研究有机无机肥配施对土壤C、N和P周转相关的酶活性(β-1,4-葡萄糖苷酶,BG;β-1,4-N-乙酰基氨基葡萄糖苷酶,NAG;L-亮氨酸氨基肽酶,LAP;碱性磷酸酶,PHOS)及其化学计量特征的影响,并分析其与环境因子和微生物碳利用率之间的关系.试验共设4个处理,分别为不施肥(CK)、单施氮磷钾化肥(NPK)、单施有机肥(M)和化肥配施有机肥(MNPK).结果表明:①在果树各生育期,施用有机肥处理(MNPK和M)的微生物量碳(microC)含量显著高于不施有机肥处理(CK和NPK);微生物量氮(microN)含量,在萌芽期NPK、MNPK和M处理比CK处理分别增加了89%、269%和213%(P<0.05).②CK处理在萌芽期有较高的叶片ω(N)和ω(P)(29.8 g·kg^(-1)和2.17 g·kg^(-1)),并且仅果树萌芽期的叶片P含量与土壤有效磷(AP)含量呈显著负相关.③土壤酶化学计量分析的所有数据点均在1:1线以上,表现为微生物群落存在较强的P限制;果树生长期,矢量长度和角度的变化范围分别为0.56~0.79和59.3°~67.7°,且研究中矢量角度均>45°,也体现了微生物存在较强的磷限制.④RDA和随机森林模型分析结果表明,有机碳和速效氮(AN)是影响矢量长度的主要理化因子,AP、AN和土壤含水量是影响矢量角度的主要理化因子;SEM分析表明,AN和可溶性有机碳(DOC)直接影响microC和microN,AP直接影响microP和microN,DOC和AP直接影响矢量长度,AP和microN直接影响矢量角度;微生物碳利用率与矢量长度呈显著正相关,与矢量角度呈显著负相关.综上所述,有机无机肥配施通过影响果树不同生育期土壤碳和磷含量,调控微生物碳、磷代谢进而影响微生物碳利用率,为�Soil microbial carbon(C),nitrogen(N),and phosphorus(P)nutrient requirements and metabolic limitations are closely related to the availability of environmental nutrients.However,it is unclear how manure and chemical fertilization shift nutrient limitations for microbes in terms of the soil enzymatic stoichiometry in an apple orchard.Therefore,based on the long-term experiment located in an apple orchard established in 2008,this study applied the theory and method of soil enzyme stoichiometry to systematically investigate the effects of the combined application of manure and chemical fertilizers on soil C,N,and P turnover-related enzyme activities(β-1,4-glucosidase,BG;leucine aminopeptidase,NAG;β-1,4-N-acetylglucosaminidase,LAP;and acid or alkaline phosphatase,PHOS)and their stoichiometric characteristics and analyzed their relationships with environmental factors and microbial carbon use efficiency.The experiment was designed with four treatments,such as,no fertilization input as the control(CK),single application of chemical fertilizer(NPK),combined application of manure and chemical fertilizer(MNPK),and single application of manure(M).The results revealed that:①at different growth stages of fruit trees,the soil microbial biomass C(microC)content of manure fertilizer treatments(MNPK and M)was significantly higher than that of no manure fertilizer treatments(CK and NPK).The content of microbial biomass N(microN)in the NPK,MNPK,and M treatments increased by 89%,269%,and 213%,respectively,compared with that in CK(P<0.05).②Compared with those in the fertilization treatments,CK had higher leaf N and P contents(29.8 g·kg^(-1)and 2.17 g·kg^(-1))at the germination stage,and the leaf P content at the germination stage alone was significantly negatively correlated with soil available phosphorus(AP)content.③Soil enzyme stoichiometry analysis demonstrated that all data points in this study were above the 1:1 line,indicating that microbial communities had a strong phosphorus limitation.The range of vector length and

关 键 词：碳和磷限制 碳利用效率 酶活性及化学计量 微生物代谢 土壤理化性质 

分 类 号：X171.1[环境科学与工程—环境科学]