摘要
[目的]揭示不同种植方式对土壤细菌群落结构及下茬魔芋生长的影响,为合理利用种植方式改善土壤微生态环境及维持魔芋的可持续种植提供科学依据.[方法]利用高通量测序技术分析未种植过魔芋(N)、前茬作物为魔芋(R)、种植魔芋后轮作1茬玉米(L1)和种植魔芋后轮作2茬玉米(L2)4种种植方式下土壤细菌群落结构和多样性的差异;种植下茬魔芋前采集土壤样品测定土壤理化性质,调查测定魔芋出苗率、株高、叶长、存苗率和单株块茎鲜重,探究不同种植方式形成的土壤微生态对下茬魔芋生长的影响.[结果]R处理的土壤电导率、有机质、碱解氮和速效钾含量显著高于N和L2处理(P<0.05,下同),pH则显著低于N和L2处理.4种种植方式土壤细菌群落的Sobs指数、ACE指数和Shannon指数均为N处理>L2处理>L1处理>R处理.主坐标分析结果显示R和L1处理的土壤细菌群落结构较相似,与N和L2处理的土壤细菌群落结构存在明显差异.N处理的变形菌门(Proteobacteria)、黏球菌门(Myxo-coccota)和芽单胞菌门(Gemmatimonadota)相对丰度显著高于R处理,绿弯菌门(Chloroflexi)相对丰度则显著低于R处理;但这4个优势细菌门的相对丰度在N和L2处理间差异均不显著(P>0.05,下同).相关分析结果显示,土壤pH、电导率及有机质、碱解氮、有效磷和速效钾含量与芽孢杆菌属(Bacillus)、盖亚菌属(Gaiella)、土壤红杆菌属(Solirubrobacter)、MND1和斯科曼氏球菌属(Skermanella)等土壤优势细菌属的相对丰度呈显著或极显著(P<0.01,P<0.001)相关.N处理与L2处理的下茬魔芋出苗率、存苗率、株高、叶长和单株块茎鲜重差异均不显著,但均显著高于R处理.[结论]种植魔芋后轮作2茬玉米的种植方式能通过调控土壤微生态来恢复土壤健康、促进下茬魔芋生长,有效缓解魔芋连作障碍的危害.
Abstract
[Objective]To explore the effects of different cropping systems on soil bacterial community structure and growth of Amorphophallus konjac in the next crop,so as to provide scientific basis for improving soil microecological en-vironment by rational cropping systems,and maintaining sustainable planting of A.konjac.[Method]The high-throughput sequencing technology was used to analyze the differences of soil bacterial community structure and diversity under the cropping systems:A.konjac has never been cultivated(N),A.konjac was planted as the previous crop(R),maize was planted for 1 year after A.konjac has been harvested(L1),and maize was planted for 2 years after A.konjac has been harvested(L2).The effects of soil microecology formed under different planting systems on the growth of A.konjac in the next crop were studied by analyzing the physical and chemical properties of soil before planting A.konjac in the next crop,and the seed germination rate,seedling survival rate,plant height,leaf length,fresh weight of tuber per plant of A.konjac.[Result]The electrical conductivity,contents of organic matter,alkali hydrolyzed nitrogen,available potassium in the soil sample of R were significantly higher than those in the soil samples of N and L2(P<0.05,the same below).While pH in the soil sample of R was significantly lower than that in the soil samples of N and L2.The Sobs index,ACE index and Shannon index of soil bacterial communities in the 4 different cropping systems were N>L2>L1>R.Principal coordinates analysis(PCoA)showed that the bacterial community structures of R and L1 treatments were similar,and were both greatly different from those of N and L2 treatments.The relative abundance of Proteobacteria,Myxococcota and Gemmati-monadota in the soil sample of N treatment was significantly higher than that in R treatment,but the relative abundance of Chloroflexi in the soil sample of N treatment was significantly lower than that in R treatment.However,the relative abun-dance of these 4 dominant bacterial phyla did not differ significantly between N and L2 treatments(P>0.05,the same below).Correlation analysis showed that soil pH,electrical conductivity,organic matter content,alkali hydrolytic nitrogen content,available phosphorus content and available potassium content were significantly or extremely significantly(P<0.01,P<0.001)correlated with the relative abundance of dominant bacterial genera in soils such as Bacillus,Gaiella,Solirubrobacter,MND1 and Skermanella.There were no significant differences in the seed germination rate,seedling survival rate,plant height,leaf length and fresh weight of tuber per plant of A.konjac in the next crop between N and L2,and they were both significantly greater than those of R treatment.[Conclusion]The cropping system of maize being planted for 2 years after harvesting A.konjac can restore soil health,promote the growth of A.konjac in the next crop,and effectively alleviate the continuous cropping obstacle of A.konjac by regulating soil microecology.
维普
万方数据