摘要
【目的】针对内蒙古河套灌区农民自愿放弃秋浇造成干地面积逐渐增多的现象,通过调查研究不同秋浇年限对盐碱土壤细菌群落组成差异的影响,为灌区盐碱地改良与秋浇制度改革提供科学依据。【方法】选取盐荒地(CK)、一直秋浇(AUI1)、隔2-3年秋浇(AUI2)、3-4年不秋浇(AUI3)以及6-7年不秋浇(AUI4)5种类型的典型地块,采用高通量测序(Illumina HiSeq)技术,分析不同秋浇年限处理下土壤细菌群落的变化特征,并对土壤化学性质与细菌群落进行了冗余分析以及与群落组成的相关性分析。【结果】AUI1和AUI2处理对降低0-30 cm土层盐分含量最显著,分别比CK、AUI3、AUI4降低了128.82%和29.04%、108.76%和17.72%、108.44%和17.55%,在30-40 cm土层AUI1处理的盐分含量显著低于其他处理;各个土层的pH值均以AUI2处理最低,其0-40 cm土层p H平均值较CK、AUI1、AUI3、AUI4处理分别显著降低了0.28、0.32、0.16、0.88个单位(P<0.05)。另外,AUI2处理0-40 cm土层微生物量碳平均含量分别较CK、AUI1、AUI3、AUI4提高了252.89%、148.59%、58.10%和60.10%,可溶性有机碳平均含量分别提高了48.41%、29.42%、6.01%和14.27%(P<0.05)。AUI1与AUI2处理间的丰富度指数(ACE和Chao1)显著高于CK、AUI3和AUI4处理(P<0.05)。变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)和拟杆菌门(Bacteroidetes)为不同秋浇年限处理的3大优势菌门,占所有菌门的53.93%,而AUI2、AUI3处理分别有利于增加拟杆菌门、酸杆菌门的丰度(P<0.05)。相关性分析结果表明,变形菌门(Proteobacteria)和绿弯菌门(Chloroflexi)与土壤微生物量碳和可溶性有机碳均具有很强的负相关性,其中与微生物量碳的相关系数分别为(r=-0.559**和-0.522*),与可溶性有机碳的相关系数分别为(r=-0.795**和-0.820**);而放线菌门(Actinobacteria)、奇古菌门(Thaumarchaeota)、厚壁菌门(Firmicutes)和疣微菌门(Verrucomicrobia)均与土壤盐分呈显著负相关,与土壤微生物量碳和可溶性有机碳呈显著正相关。因子分析显示,土壤盐分、pH、微生物量和可溶性有机碳总共解释了97%的群落变化,成为土壤细菌群落组成变化的主控因子,贡献率依次为:土壤盐分>pH>微生物量碳>可溶性有机碳。【结论】隔2-3年秋浇(AUI2)处理不仅可以有效降低耕层土壤盐分并能使0-40 cm土层微生物量碳和可溶性有机碳含量显著增加,而且还可提高土壤优势菌群中拟杆菌门的相对丰度。综上所述,隔2-3年秋浇(AUI2)是河套地区兼顾盐碱土壤改良与节水的优化措施。
【Objective】Considering the phenomenon that farmers voluntarily gave up the water irrigation in autumn,We investigated the effects of different autumn irrigation years on soil bacterial community composition in Inner Mongolia Hetao Irrigation District,so as to provide corresponding scientific support for the improvement of saline-alkali land and reformation of autumn irrigation system.【Method】By selecting five types of typical plots,including wasteland(CK),always irrigation in autumn(AUI1),2-3 years with autumn irrigation(AUI2),3-4 years without autumn irrigation(AUI3)and 6-7 years without autumn irrigation(AUI4),the characteristics of soil bacteria in different autumn irrigation years were analyzed by high-throughput sequencing(Illumina HiSeq),and redundantly and correlation analysis of the soil chemical properties with bacterial communities and with community composition were followed.【Result】The results showed that the salt content of AUI1 and AUI2 treatments were significantly reduced in 0-30 cm soil layer,compared with CK,AUI3 and AUI4,which were reduced by 128.82%and 29.04%,108.76%and 17.72%,108.44%and 17.55%,respectively.The salt content of AUI1 treatment was significantly reduced than that of other treatments in 30-40 cm soil layer;the pH of AUI2 treatment was the lowest in each soil layer,and compared with CK,AUI1,AUI3 and AUI4 treatments,which reduced by 0.28,0.32,0.16 and 0.88 units,respectively(P<0.05).Compared with CK,AUI1,AUI3 and AUI4 treatments,the soil microbial biomass carbon content of AUI2 treatment were increased by 252.89%,148.59%,58.10%and 60.10%,respectively,and the soluble organic carbon content increased by 48.41%,29.42%,6.01%and 4.27%,respectively(P<0.05).The abundance index(ACE and Chao1)of AUI1 and AUI2 treatments were significantly higher than CK,AUI3 and AUI4 treatments(P<0.05).Proteobacteria,Acidobacteria and Bacteroidetes were the three dominant bacteria that were treated in different autumn years,accounting for 53.93%of all bacteria,while AUI2 and AUI3 treatment are beneficial to increase the Bacteroidetes and Acidobacteria relative abundance(P<0.05).Correlation analysis showed that Proteobacteria and Chloroflexi were significantly negatively correlated with soil microbial biomass carbon and soluble organic carbon,and the correlation coefficient with microbial biomass carbon were(r=-0.559**and-0.522*),the correlation coefficients with soluble organic carbon were(r=-0.795**and-0.820**),respectively;Actinobacteria,Thaumarchaeota,Firmicutes and Verrucomicrobia were significantly negatively correlated with soil salinity and significantly positively correlated with soil microbial biomass carbon and dissolved organic carbon.Factor analysis showed that soil salinity,pH,microbial biomass and soluble organic carbon were main environmental factors on the soil bacterial community structure,total explaining 97%of the community changes.The order of contribution rate was soil SC>pH>MBC>SOC.【Conclusion】Comprehensive consideration,the 2-3 years with autumn irrigation(AUI2)treatment could not only effectively reduce the soil salinity and significantly increase the microbial biomass carbon and soluble organic carbon content in 0-40 cm soil layer,but also improve the relative abundance of the dominant bacteria.In summary,the autumn irrigation(AUI2)was an optimization measure for the improvement of saline soil and water conservation in Hetao area.
作者
张晓丽
张宏媛
卢闯
逄焕成
靳存旺
高喜
程挨平
李玉义
ZHANG XiaoLi;ZHANG HongYuan;LU Chuang;PANG HuanCheng;JIN CunWang;GAO Xi;CHENG AiPing;LI YuYi(Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 100081;Wuyuan County Agricultural and Animal Husbandry Technology Promotion Center,Wuyuan 015100,Inner Mongolia;Yihe Canal Center of Yichang Experimental Station of Inner Mongolia Hetao Irrigation District,Wuyuan 015100,Inner Mongolia)
出处
《中国农业科学》
CAS
CSCD
北大核心
2019年第19期3380-3392,共13页
Scientia Agricultura Sinica
基金
国家自然科学基金(31871584,31471455)
国家重点研发计划项目(2016YFC0501302)
关键词
秋浇
土壤细菌
群落结构
多样性
盐碱土
高通量测序
内蒙古河套灌区
autumn irrigation
soil bacterial
community structure
bacterial diversity
saline-alkali soil
IlluminaMiSeq
Inner Mongolia Hetao Irrigation District