| 长期秸秆还田对下茬还田秸秆的降解及土壤微生物群落的影响 |
| 摘要点击 1967 全文点击 285 投稿时间：2023-12-22 修订日期：2024-03-29 |
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| 中文关键词 秸秆还田 残留效应 秸秆降解 微生物群落 网络分析 |
| 英文关键词 straw incorporation legacy effects straw degradation microbial community network analysis |
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| 中文摘要 |
| 探究长期秸秆还田土壤残留效应对秸秆降解及微生物群落的影响. 以连续15 a秸秆还田土壤（SS）和秸秆未还田土壤（NS）为研究对象,通过模拟试验分析两种土壤同时秸秆还田后秸秆的降解情况和土壤微生物种群的变化. 采用沙袋法测定秸秆降解率,稀释涂布平板法测定土壤可培养微生物数量,高通量测序技术分析土壤微生物群落多样性和结构. 结果表明,与NS相比,SS显著增加15 d和30 d秸秆降解率,增幅为14.16%和26.57%；显著增加0~60 d内土壤可培养真菌的数量,增幅为43.10%~185.92%；显著增加0 d和42 d和56 d时纤维素降解菌数量,增幅为55.12%~92.04%. 秸秆还田7 d时,SS中的细菌ACE指数、真菌ACE指数和Chao1指数低于NS,说明SS土壤中微生物群落丰富度显著降低. 在门水平上,SS中酸杆菌门、浮霉菌门和己科河菌门等细菌门相对丰度显著增加,增幅为25.92%~45.17%；油壶菌门、捕虫霉亚门和球囊菌门等真菌门相对丰度显著增加,增幅为12.09%~176.00%. 在属水平上,SS中Subgroup6纲未定属和罗库菌目未定属等细菌属相对丰度显著增加,增幅为28.91%~31.26%；拟青霉菌属、被孢霉菌属和青霉菌属等真菌属相对丰度显著增加,增幅为2.98%~8.79%. 分子生态网络分析表明,SS细菌网络互作程度更高、网络连接更紧密,真菌网络则呈现更加复杂和稳定的结构. RDA结果显示,土壤微生物群落组成与秸秆降解率呈极显著相关. SS对下茬还田秸秆的降解、土壤可培养微生物数量和种群结构变化在一定时间内表现出明显的残留效应,其微生物菌群更利于下茬还田秸秆的降解. |
| 英文摘要 |
| Straw incorporation can improve soil fertility and soil structure. While numerous studies have explored the immediate impacts of straw return on soil properties and crop production, the legacy effects of long-term straw return remain less understood. In this study, the straw returning soil of a continuous 15 years （SS） and non-straw returning soil （NS） were collected from Dahe Experimental Station of Hebei Academy of Agriculture and Forestry Sciences in China. The simulation experiments of subsequent straw return were carried out in pots by adding straw to the two types of soil （SS and NS）, in which the degradation rate of straw was determined using the sandbag method, the number of culturable microorganisms was counted through a dilution coating plate, and microbial communities were characterized using high-throughput sequencing. The findings revealed that compared with that in NS, SS significantly increased the degradation rate of 15 d and 30 d straw by 14.16% and 26.57%； the number of soil culturable fungi in 0-60 days by 43.10%-185.92%； and the number of cellulose-degrading bacteria by 55.12%-92.04% at 0 d, 42 d, and 56 d. Additionally, after straw returning for seven days, the bacterial ACE index, fungal ACE index, and Chao1 index in SS were lower than those in NS, indicating that the microbial community richness in SS was significantly reduced. At the phylum level of bacteria, the relative abundances of Acidobacteria, Rokubacteria, and Planctomycetes in SS increased observably, with an increase of 25.92%-45.17%. The relative abundances of the phyla of fungi such as Olpidiomycota, Zoopagomycota, and Glomeromycota increased markedly, with an increase of 12.09%-176.00%. At the genus level of bacteria, the relative abundances of uncultured_bacterium_c_Subgroup_6 and uncultured_bacterium_o_Rokubacteriales in SS increased significantly, with an increase of 28.91%-31.26%, and at the genus level of fungi, the relative abundances of Paecilomyces, Penicillium, and Moesziomyces were significantly increased by 2.98%-8.79%. Network analysis showed the SS bacterial network had a higher interaction degree and network connection, and the fungal network structure was more complex and stable than that of the NS. RDA results showed that soil microbial community composition was significantly correlated with straw degradation rate. SS showed obvious legacy effects on straw degradation, the number of soil culturable microorganisms, and population structure in a certain period, and the microbial flora of SS was more conducive to the degradation of the straws. |
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