施用不同有机物料对砂质土壤玉米成熟期根际细菌群落变化的影响

Effects of application different organic materials on the bacterial community of maize rhizosphere in sandy soil at the maturity stage

为探究有机物料还田后土壤理化性质对细菌群落变化的影响,在华北平原砂质土壤玉米成熟期分别以秸秆还田(ST)和单施化肥(CF)为主、副对照,设置猪粪(PM)、沼渣(BR)和秸秆生物炭(BC)3种有机物料还田处理,利用Illumina高通量测序技术分析根际土壤细菌群落结构。结果表明:1)玉米成熟期根际土壤细菌群落丰富度的2个指标(Chao 1和ACE)由高到低均为:PM>BR>ST>BC>CF,但沼渣和生物炭处理的土壤细菌群落多样性(Shannon)均显著高于猪粪处理。2)沼渣、生物炭和对照组(秸秆和化肥处理)的土壤细菌优势菌门均为放线菌门(Actinobacteriota)、变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)和绿弯菌门(Chloroflexi),优势菌门的累计丰度为71.53%~80.31%;而猪粪处理的土壤细菌优势菌门以厚壁菌门(Firmicutes)为首,其余依次为放线菌门、变形菌门、酸杆菌门和绿弯菌门,优势菌门的累计丰度为85.61%。3)土壤有效磷是影响土壤细菌群落结构变化的主效环境因子(P<0.05),与厚壁菌门的梭菌属(Clostridium)和土孢杆菌属(Terrisporobacter)的相对丰度均呈显著正相关,其中猪粪处理的土壤有效磷含量显著高于其他处理;生物炭处理显著增加土壤pH和有机质含量,沼渣处理增加土壤水分含量但不显著,生物炭和沼渣处理显著上调放线菌门相关菌属的相对丰度。综上,猪粪处理虽然显著提高土壤细菌群落的丰富度,但是导致菌落的多样性显著下降,生物炭处理则与之相反;沼渣处理也显著提高土壤细菌群落的丰富度和多样性。综上,合理施用沼渣还田可作为改良华北平原砂质瘠薄型农田的首选方式。

The aim of this study was to investigate the effects of soil physicochemical properties after organic materials were returned to the field on the changes of bacterial community.In this study,straw(ST)returning was taken as the main control and the chemical fertilizer(CF)treatment as the secondary control of maize in sandy soil at the maturity stage in North China Plain.Three organic material returning treatments were set up as follows:pig manure(PM),biogas residue(BR)and biochar(BC).The bacterial community structures of rhizosphere soil were analyzed by highthroughput sequencing.The results showed that:1)The two abundance indexes of bacterial community,Chao 1 and ACE,at the maize maturity stage in rhizosphere soil were decreased in the following order:PM>BR>ST>BC>CF.However,the diversity(Shannon)of soil bacterial community in BR and BC treatments were significantly higher than that in PM treatment.2)Actinobacteriota,Proteobacteria,Acidobacteria and Chloroflexi were the dominant phylum among the soil bacterial community in BR,BC and control groups,and the cumulative abundance of the dominant phyla were between 71.53% and 80.31%.Firmicutes,Actinobacteriota,Proteobacteria,Acidobacteria and Chloroflexi were the dominant phylum in PM treatment,and the cumulative abundance of the dominant phyla was 85.61%.3)Soil available phosphorus was the main environment factor(P<0.05)affecting the changes of bacterial community structures.Soil available phosphorus was significantly positively correlated with the relative abundance of Clostridium and Terrisporobacter(belong to Firmicutes).The content of soil available phosphorus in PM treatment was significantly higher than that in other treatments.The contents of soil pH and organic matter were significantly increased in BC treatment,and the content of soil moisture was non-significantly increased in BR treatment.The relative abundance of bacteria genus,which was closely related to Actinobacteriota,were significantly increased in BC and BR treatments.In addition,PM treatment significantly increased the abundance of soil bacterial community but led to significant decline on the diversity of bacterial community,while the trends found in BC treatment were the opposite.The abundance and diversity of soil bacterial community were significantly increased in BR treatment.In conclusion,the rational application of biogas residue amendment is the first choice to improve the sandy and barren type farmland in North China Plain.