不同轮作模式对桔梗生长、根际土壤微生物及土壤酶活性的影响

为研究不同轮作模式对桔梗根际土壤微生物及土壤酶活性的影响，从土壤微生态角度探寻一种无公害防治桔梗连作障碍的方式，以二年生桔梗为试材，采用盆栽试验的方法，以桔梗-桔梗（JG-JG）为对照，研究了桔梗-北沙参（JG-SS）、桔梗-玉米（JG-YM）、桔梗-防风（JG-FF）和桔梗-牛膝（JG-NX）不同轮作模式下对桔梗生长及土壤微生物和土壤酶活性的影响，分析筛选出桔梗的最优轮作模式。研究发现，JG-YM和JG-NX轮作模式下桔梗各生物量指标均优于其他处理；通过不同轮作种植模式对桔梗根际土壤微生物数量的影响研究发现，JG-SS、JG-YM、JG-NX、JG-FF细菌数量高于桔梗连作处理；JG-YM和JG-FF整体放线菌数量变化高于桔梗连作处理；JG-YM和JG-NX真菌数量与桔梗连作处理相比增长最为缓慢。通过不同轮作种植模式对桔梗根际土壤酶活性的影响研究发现，JG-NX的脲酶、蔗糖酶和纤维素酶活性高于其他四种处理。通过测定不同轮作模式下的桔梗生物量、桔梗根际土壤微生物数量和土壤酶活性，表明桔梗与牛膝或玉米轮作种植能改善种植土壤环境，缓解桔梗的连作障碍，可为桔梗的规范化种植奠定基础。

Effects of different rotation patterns on the growth， rhizosphere soil microorganisms， and soil enzyme activities of Platycodon grandiflorum （Jacq.） A. DC.

To study the effects of different rotation modes on soil microorganisms and soil enzyme activities in the rhizosphere of Platycodon grandiflorum （JG）， and to explore a pollution-free prevention and control method for continuous cropping obstacles of JG from the perspective of soil microecology， the biennial JG was used as the test material， and pot experiment method was used to study the effects of different rotation modes of JG-SS（Beishashen），JG-YM（Yumi），JG-FF（Fangfeng） and JG-NX（Niuxi） on JG growth， soil microorganisms and soil enzyme activities， using JG-JG as the control. The optimal rotation modes were analyzed and selected. It was found that the biomass indicators of modes JG-YM and JG-NX were superior to other modes. The bacterial quanlity of modes JG-SS， JG-YM， JG-NX， and JG-FF was higher than that of mode JG-JG. The overall changes in the number of actinomycetes in modes JG-YM and JG-FF were higher than those in mode JG-JG. The growth of fungal numbers of modes JG-YM and JG-NX was the slowest compared to that in mode JG-JG. The activities of urease， sucrase， and cellulase in mode JG-NX were higher than those of the other four modes. This study measured the biomass， soil microbial count， and soil enzyme activity of JG under different rotation modes， indicating that rotation planting of JG with Achyranthes bidentata（NX） or zea mays（YM） can improve the planting soil environment， alleviate the continuous cropping obstacles of JG， and lay the foundation for standardized planting of JG.