【摘要】 为了探索连续多年免耕轮作对土壤养分与微生物的影响，以麦稻水旱轮作免耕试验为对象，采用常规土壤养分测定法、土壤微生物宏基因组测序技术及京都基因和基因组百科全书(KEGG)数据库、冗余(RDA)分析等方法，对连续多年田间保留农作物残茬免耕及传统耕作土壤的养分、微生物种群、酶活性等进行了检测分析。结果表明，连续13年田间保留农作物秸秆、残茬免耕轮作与传统耕作轮作0～20 cm土壤微生物种群结构丰度在农作物不同生长发育时期发生了变化，第一核心种群的变形菌门(Proteobacteria)、酸性杆菌门(Acidobacteria)丰度最高，呈增加趋势；第二核心种群的放线菌门(Actinobacteria)、绿弯菌门(Chloroflexi)丰度呈下降趋势；连续多年免耕轮作处理土壤中心土壤脲酶、蔗糖酶、蛋白酶含量分别比传统耕作处理提高了4.9%、22.8%、21.7%；免耕轮作处理的作物在绝大部分生长阶段与土壤酶的关联性优于传统耕作轮作处理。免耕处理Z4与传统耕种处理T4比较，土壤有机质、全氮、全磷、水解性氮、有效磷含量分别提高了27.7%、20.3%、16.1%、30.8%、19.3%；两种土壤的微生物代谢通路差异主要表现为氨基酸类通路，免耕轮作处理的绝大多数氨基酸类通路在第1时期(小麦拔节期)和第3时期(水稻孕穗期)比传统耕作轮作激活程度强的差异达到显著或极显著水平。在免耕轮作处理中，硝基螺菌属(Nitrospira)、厌氧黏细菌属(Anaromyxobacter)与全钾、速效钾、有机质、全氮、水解性氮含量，鞘氨醇单胞菌属(Sphingomonas)与有效磷含量呈正相关。连续多年田间保留作物残茬、秸秆，为微生物提供了较多的“食物”，以及连续多年免耕轮作措施减少土壤微生物生存环境的破坏是培肥地力的根本原因。而合理轮作免耕土壤中的变形菌门、酸性杆菌门等核心优势细菌种群，以及土壤酶的催化作用优于传统耕作，它们共同促进了土壤有机质和土壤养分转化和循环是提高土壤肥力的推动力。更多还原

【Abstract】 In order to explore the effects of continuous years zero-tillage and rotation on soil nutrient and microorganisms,an experiment of zero-tillage(Z)with crop residues and part of straws,which was maintained in the field,and traditional tillage(T)on winter wheat-paddy rice rotation system was conducted for consecutive years in Ningxia Yellow River Irrigation Basin. The methods of conventional soil nutrient determination,metagenomic sequencing,KEGG database and RDA(Redundancy analysis)were used. The experiment focused on soil nutrients,soil microbial communities and their metabolic pathways,and soil enzymes. The results showed that the abundance of soil microbial population structure in 0-20 cm soil was changed in different growth stages of crops. The abundance of Proteobacteria and Acidobacter in the first core population was the highest,showing an increasing trend. However,the second core population,the abundance of Actinobacteria and Chloroflexi showed a decreasing trend. The treatment of rotation and zero-tillage for continuous years increased the contents of urease,sucrase protease and catalase increased than treatment of traditional tillage by 4.9%,22.8% and 21.7%,respectively. The correlation between soil enzymes and crops treated with zero-till rotation was better than treatment of traditional tillage rotation in most growth stages. Meanwhile,the contents of organic matter,total nitrogen,total phosphorus,hydrolyzable nitrogen and available phosphorus in zero-tillage(Z)4 were increased than traditional tillage(T)4 by 27.7%,20.3%,16.1%,30.8% and 19.3%,respectively. However,the difference of soil microbial metabolic pathway between treatments of Z and T was mainly represented by amino acid pathway. The activation degree of most amino acid pathways of Z was significantly higher than T at the first stage(wheat jointing stage) and at the third stage(rice booting stage). In the treatment Z,the Nitrospira and the Anaromyxobacter were more positively correlated with contents of the total potassium,available potassium,organic matter,total nitrogen and hydrolyzable nitrogen. Whereas,the Sphingomonas was more positively correlated with available phosphorus content only. The results also suggested that the correlation between treatment Z and soil enzyme was better than treatment T in most crop growth stages. In conclusion,the fundamental reason for improving soil fertility was maintaining crop residues and straws in the field for many years,provided more “food” for microorganisms,as well as reduced the disturbance to the living environment of soil microorganisms in treatment Z. However,the driving force factors to improve the fertility of soil were that,Proteobacter,Acidobacter and other core dominant bacterial populations in the soil of reasonable rotation system with zero tillage,as well as the catalytic effect of soil enzymes,were better than the traditional tillage,which jointly promoted the transformation and circulation of soil organic matter and soil nutrients.更多还原