不同前作对植烟土壤养分含量、酶活性及细菌群落结构的影响

Effect of Different Previous Crops on the Nutrient Content,Enzyme Activity and Bacterial Community Structure in Tobacco Growing Soil

【目的】研究不同前作对土壤生物化学性质的影响。【方法】利用化学和酶学分析及16S多样性测序技术,分析种植7年的不同前作[荞麦(FB)、油菜(FR)、小麦(FW)和绿肥(FG)]烟田土壤的养分、酶活性及细菌群落结构组成。【结果】(1) FR烟田土壤的有机质、全氮、碱解氮和有效磷含量最高,分别为30.04 g/kg、1.62 g/kg、143.50 mg/kg和88.09 mg/kg,FG烟田次之,但FG烟田速效钾的含量最高(240.10 mg/kg);FG烟田土壤蛋白酶和磷酸酶的活性最高,分别为709.02μg/(g·d)(酪氨酸)和306.60μg/(g·h)(对硝基酚),而其脲酶和蔗糖酶的活性仅低于FW烟田,且无显著性差异(P>0.05)。(2)在细菌群落组成上,FB、FG、FW和FR烟田分别检测出770、670、654和597属,归属于Actinobacteria、Proteobacteria、Chloroflexi和Acidobacteria等36门,其中Actionbacteria和Proteobacteria相对丰度最高,分别为26.87%~45.21%和25.82%~30.69%,Treptomyces、Bradyrhizobium、Bacillus和Mycobacterium等拮抗菌和Bradyrhizobium、Rhizobium和Paenibacillus等固氮菌在FB烟田土壤细菌群落的相对丰度最高。【结论】不同前作对烟田土壤理化性质、酶活性和细菌群落结构的影响不同,绿肥提高了土壤有机质和养分含量以及酶活性;而荞麦改善和提高了烟田土壤细菌种群结构和多样性。

[Purpose]The effects of different previous crops on the soil biochemical properties were studied.[ Method]Using chemical, enzymatic analysis and 16 S diversity sequencing techniques, the soil nutrient, enzyme activity and bacterial community structure of tobacco fields with fagopyrum(FB), rape(FR), wheat(FW) and green manure(FG) were analyzed after seven years.[Results](1) The contents of organic matter, total nitrogen, alkali-hydrolyzed nitrogen and available phosphorus were the highest in FR tobacco field, which respectively were 30.04 g/kg, 1.62 g/kg,143.50 mg/kg and 88.09 mg/kg, followed by FG tobacco field, but the content of available potassium was 240.10 mg/kg, and the activities of protease and phosphatase in FG tobacco field were the highest, which were 709.02 μg/(g·d)(tyrosine) and 306.60 μg/(g·h)(p-nitroph), respectively.(2) The activities of urease and invertase were lower than those of FW tobacco field, and there was no significant difference(P>0.05). In terms of bacterial community composition, 770, 670, 654 and 597 genera were detected in FB, FG, FW and FR tobacco fields, belonging to 36 taxa, including Actinobacteria, Proteobacteria, Chloroflexi and Acidobacteria. Among them, the abundance of Actionbacteria and Proteobacteria were the highest, respectively ranging from 26.87% to 45.21% and 25.82% to30.69%. Antagonistic bacteria such as Treptomyces, Bradyrhizobium, Bacillus and Mycobacterium and nitrogen-bacteria such as Bradyrhizobium, Rhizobium and Paenibacillus had the highest relative abundance of bacterial community in FB tobacco field soil.[Conclusion]The effects of different preceding cropping on the soil physical and chemical properties, enzyme activities and bacterial community structure were different. Green manure improved soil organic matter, nutrients and enzyme activities, while buckwheat improved soil bacterial population structure and diversity, and the relative abundance of probiotics was higher.