不同改良材料对黄河三角洲耕层土壤理化性质及微生物多样性的影响

Effects of Different Modified Materials on Physical and Chemical Properties and Microbial Diversity of Coastal Saline Soil in the Yellow River Delta

为提高黄河三角洲滨海低产田耕层有机质含量,探究施用不同材料对研究区域土壤改良效果,设置WM(木本泥炭+腐熟秸秆)、BS(生物炭+腐熟秸秆)、OS(有机肥+腐熟秸秆)、S(腐熟秸秆)、CK(常规施肥)5种不同类型改良材料处理进行田间试验,改良材料用量均为30 t hm^-2,腐熟秸秆用量为14 t hm^-2。经过两茬玉米种植后,采集土壤样品,分析了土壤微生物及养分变化。研究结果表明,木本泥炭材料+腐熟秸秆处理的Chao1、Simpson指数、Shannon指数提高,土壤微生物多样性增加。各处理中土壤细菌类群主要有Proteobacteria(变形菌门)、Acidobacteria(酸杆菌门)、Actinobacteria(放线菌门)、Chloroflexi(绿弯菌门)、Bacteroidetes(拟杆菌门),其合计量的相对丰度在5种处理WM、BS、OS、S、CK中分别为26%、16%、15%、15%、9%。在5种处理中相对占比较高的六种优势菌属为Exiguobacterium(微小杆菌属)、Citrobacter(柠檬酸菌属)、Pseudomonas(假单胞杆菌属)、Acinetobacter(不动杆菌属)、Kaistobacter、Pontibacter。冗余分析发现与有机质、可溶性有机碳等指标相关性最好的浮霉菌门(Planctomycetes)、疣微菌门(Verrucomicrobia)、芽单胞菌门(Gemmatimonadetes)微生物在腐熟秸秆处理中OTU指数最高。在施加不同改良材料处理中,木本泥炭材料+腐熟秸秆提高碱解氮、有机质含量效果显著,有机肥+腐熟秸秆处理提高土壤溶解性有机碳效果显著。

In order to improve the organic matter content of the low-yield field in the Yellow River Delta,the improvement effect of different materials was explored on the study area.The experiment contained five treatments including WM(woody peat+rotten straw),BS(biochar+rotten straw),OS(organic fertilizer+rotten straw),S(rotten straw),CK(conventional fertilization).Soil fertility indices and high-throughput sequencing were measured.The results of microbial diversity and community structure analysis showed woody peat material+rotten straw(WM)demonstrated better microbial diversity than other treatments by the Chao1 index,Simpson index and Shannon index.The soil bacterial groups of each treatment mainly included Proteobacteria,Acidobacteria,Actinobacteria,Chloroflexi,Bacteroidetes,and Bacteroidetes.And the abundance ratio of the soil bacterial group was 26%,16%,15%,15%,and9%,respectively.Among the five treaments,there are six dominant species,namely Exiguobacterium,Citrobacter,Pseudomonas,Acinetobacter,Acinetobacter,Kaistobacter,Pontibacter.However,it was found that the most relevant species of Planctomycetes,Verrucomicrobia,and Gemmatimonadetes were the highest OTU in straw control through RDA analysis.Woody peat material+rotten straw had significant effect on improving alkali nitrogen and organic matter,and organic fertilizer+rotten straw has significant effect on improving soil dissolved organic carbon.