长期施肥对黄土高原梯田土壤养分特征和微生物资源限制的影响  

Effects of Long-term Fertilization on Soil Nutrient Characteristics and Microbial Resource Restrictions in a Terrace on the Loess Plateau

作　　者：吴春晓 高小峰 闫本帅 梁彩群 陈佳瑞 王国梁[1,3] 刘国彬[1,3] WU Chun-xiao;GAO Xiao-feng;YAN Ben-shuai;LIANG Cai-qun;CHEN Jia-rui;WANG Guo-liang;LIU Guo-bin(Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling 712100,China;University of Chinese Academy of Sciences,Beijing 100049,China;Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,China)

机构地区：[1]中国科学院水利部水土保持研究所,杨凌712100 [2]中国科学院大学,北京100049 [3]西北农林科技大学水土保持研究所,杨凌712100

出　　处：《环境科学》2022年第1期521-529,共9页Environmental Science

基　　金：国家自然科学基金项目(42041005)。

摘　　要：长期不同施肥处理会改变土壤的理化性质和微生物生物量,但长期不同施肥对黄土高原梯田土壤微生物胞外酶活性变化和养分特征的影响尚不清楚.本研究以中国科学院安塞水土保持综合试验站长期养分定位试验样地为基础,分析了不施肥(CK)、有机肥与氮肥混施(MN)、有机肥与磷肥混施(MP)、有机肥、氮肥与磷肥混施(MNP)、单施有机肥(M)和氮肥磷肥混施(NP)对土壤微生物生物量以及土壤胞外酶活性的影响.结果表明,与CK相比,所有施肥处理都显著提高了土壤养分含量和土壤胞外酶活性.相关分析表明,土壤胞外酶活性与土壤理化性质成极显著的相关关系,冗余分析显示土壤养分和土壤微生物生物量可以分别解释土壤胞外酶活性及其化学计量比变化的79.66%和74.87%,即施肥主要是通过影响土壤肥力间接影响土壤胞外酶活性.单施有机肥或有机肥配施无机肥(M、MN、MP和MNP)均可以显著提高土壤有机碳(SOC)和土壤总氮(STN)以及碳(C)源酶、氮(N)源酶和磷(P)源酶的含量,但MNP处理会使土壤酸碱度发生改变,对微生物的生命活动产生抑制作用.矢量分析表明,所有处理的微生物群落均处于磷限制状态,MNP处理虽然可以缓解磷限制的程度,但与M和MP处理之间没有显著性差异.本研究表明,长期单施有机肥[7500 kg·(hm^(2)·a)^(-1)]可以满足旱地作物生长的养分需求,长期有机肥与磷肥混施可以缓解土壤微生物面临的资源限制,该结果对改善区域氮肥过量提供了新思路.Long-term fertilization has an important effect on soil fertility and soil microbial activity. In order to explore the effects of long-term fertilization on soil extracellular enzyme activities and nutrient characteristics in a terrace on the Loess Plateau, we based our investigation on the long-term nutrient localization plot of Ansai Soil and Water Conservation Experimental Station, Chinese Academy of Sciences. We measured the soil physicochemical properties, microbial biomass, and extracellular enzyme activities of six fertilization treatments, which included no fertilization(CK);manure and nitrogen fertilization(MN);manure and phosphate fertilization(MP);manure, nitrogen, and phosphate fertilization(MNP);manure(M);and nitrogen and phosphate fertilization(NP). The results showed that all fertilization treatments significantly increased soil nutrient content and soil extracellular enzyme activities compared with that in CK. Correlation analysis showed that extracellular enzyme activity and soil physicochemical properties had an extremely significant correlation. The redundancy analysis indicated that soil nutrient and soil microbial biomass could explain 79.66% and 74.87% of the variation in soil extracellular enzyme activity and its stoichiometric ratio, respectively. Thus, the effects of fertilization on soil fertility were primarily through influencing soil extracellular enzyme activities indirectly. M, MN, MP, and MNP significantly improved soil organic carbon(SOC);soil total nitrogen(STN);and carbon(C), nitrogen(N), and phosphorus(P) source enzyme content;however, MNP changed the soil pH, which had an inhibitory effect on microbial activities. Vector analysis showed that the microbial communities of all treatments were in the condition of P limitation. Although MNP could alleviate the extent of P limitation, there was no significant difference between M and MP. Our study indicated that long-term application of manure [7 500 kg·(hm^(2)·a)^(-1)]could meet the nutrient requirements of dryland crop growth, a

关 键 词：黄土高原 长期施肥 化学计量 胞外酶活性 梯田 

分 类 号：X171[环境科学与工程—环境科学]