Effects of farmland mulching patterns on soil microbial diversity and community structure in dryland

土壤微生物是表征土壤质量的敏感指标，采用Illumina HiSep技术分析不同覆盖方式对半湿润易旱区农田土壤微生物群落结构及多样性的影响，以期从微生物的角度评价农田不同覆盖措施对土壤质量的影响。设3种覆盖模式：平作塑料薄膜覆盖（P）、平作秸秆覆盖（S）和垄膜沟播覆盖（R），以平作不覆盖为对照（CK），研究不同覆盖模式下土壤微生物群落变化，分析各土壤理化因子与微生物群落之间的关系。研究结果表明各覆盖处理显著改变了土壤微生物的群落结构和多样性。所有土壤样品中，细菌群落的优势菌门是变形菌门（Proteobacteria）、酸杆菌门（Acidobacteria）、放线菌门（Actinobacteria），丰度分别为29.69%、28.28%和20.76%，CK处理下较高的土壤pH和低NO3-N含量抑制了土壤中酸杆菌门（Acidobacteria）的生长繁殖，而放线菌门（Actinobacteria）相对丰度为所有处理中最高。真菌群落的优势菌门是子囊菌门（Ascomycota）、担子菌门（Basidiomycota），丰度分别为59.65%和20.96%，S处理下过低的土壤温度抑制了担子菌门（Basidiomycota）生长和繁殖，其相对丰度为所有处理中最低。与CK相比，P和R处理显著提高土壤细菌的多样性和丰富度；S和R处理下土壤真菌多样性和丰富度显著增加，而P处理的土壤真菌多样性和丰富度均无显著差异。斯皮尔曼相关分析表明土壤细菌多样性主要受土壤含水量（SM）和硝态氮含量（NO3-N）影响，而土壤真菌多样性主要受土壤温度（ST）、全氮（TN）和硝态氮含量（NO3-N）影响；RDA分析表明微生物群落结构的变化主要受SM、ST、NO3-N和TN含量的影响。总的来说，R处理下土壤细菌和真菌的多样性和丰富度较CK处理显著提高，该处理下土壤中担子菌门（Basidiomycota）和球囊菌（Glomeromycota）相对丰度为所有处理中最高，两者分别形成的外生菌根和从生菌根不但促进了根部养分的吸收，而且提高了作物的抗逆性，且结果证明该处理的作物产量为最高，因此在半湿润旱作区推荐采用垄膜沟播覆盖种植方式。;Soil microbes are sensitive indicators for characterizing the quality of soil. In this study, Illumina HiSeq was used to analyze effects different mulching patterns on microbial community structure and diversity semi-humid dryland farmland soil in order evaluate impacts these measures from a perspective. The communities were tested under three comprising film (P), straw (S), ridge furrow (R), with conventional tillage without as control (CK). relationships between physical chemical characteristics analyzed. results study indicated that each treatment significantly changed diversity. dominant phyla bacterial samples among all treatments Proteobacteria, Acidobacteria, Actinobacteria abundances 29.69%, 28.28%, 20.76%, respectively. had highest relative abundance CK, but high pH low NO3-N content inhibited growth reproduction Acidobacteria fungi Ascomycota Basidiomycota 59.65% 20.96%, temperature S development Basidiomycota, its lowest treatments. Compared P R increased richness bacteria, while richness, no significant richness. Spearman's rank correlation coefficients showed mainly affected by moisture(SM) nitrate nitrogen contents(TN), temperature(ST), total nitrogen, nitrogen(NO3-N). Redundancy analysis moisture, temperature, nitrogen. general, diversities bacteria higher than CK. Glomeromycota ectomycorrhiza secondary mycorrhiza formed can enhance absorption root nutrients well improve stress resistance crops. crop yields R. Ridge is recommended planting method dry farming area.