连作与轮作下木薯产量及土壤微生物特征比较

Comparison of Cassava Yield and Soil Microbial Characteristics under Continuous Cropping and Rotation

本研究以木薯品种新选048为材料,利用高通量测序技术比较研究木薯连作与轮作的土壤微生物丰度、多样性、群落组成,并结合土壤三相比和木薯产量综合分析,探讨木薯连作障碍与土壤微生物的关系。结果表明:木薯连作土壤的细菌丰度、多样性高于轮作,连作细菌的OTU数目比轮作高23.05%,Chao1指数比轮作高463.2,香农指数比轮作高0.41;而连作真菌丰度、多样性低于轮作,轮作真菌的OTU数目比连作高19.57%,Chao1指数比连作高217.5,香农指数比连作高0.76;连作土壤容重比轮作高0.24 g/cm^3;土壤三相比,木薯连作的土壤固相比率比轮作高6.69%,液相比轮作高3.03%,而气相比率比轮作减少9.72%,差异显著(P<0.05);轮作木薯产量比连作增产11.99t/hm2,差异显著(P<0.05)。由此可见,土壤微生物组和土壤三相比的变化与木薯连作障碍有密切关系,采取栽培管理措施调节土壤微物组成和土壤三相比,是克服木薯连作障碍的有效途径。

The relationship between the continuous cropping obstacles of cassava and soil microorganisms was studied by a comprehensive analysis of the soil microbial abundance, diversity, and community composition, yield of cassava under continuous cropping and rotation using a cassava variety Xinxuan 048 as the material and using high-throughput sequencing technology in the experiment. The results showed that the bacterial abundance and diversity of cassava continuous soil were higher than that of the rotation. The number of OTUs of the bacteria for the continuous cropping was 23.05% higher than that of the rotation. The Chao1 index of the continuous cropping was 463.2 higher than that of the rotation and the Shannon index of the continuous croping was 0.41 higher than that of the rotation, while the abundance and diversity of the fungi of the continuous cropping were lower than that of the rotation. The number of OTUs of the fungi of the rotation was 19.57% higher than that of the continuous cropping, the Chao1 index of the fungi of the rotation was 217.5 higher than that of the continuous cropping, and the Shannon index of the rotation was 0.76 higher than that of the continuous crop. The soil bulk density of the continuous cropping was 0.24 g/cm^3 higher than of the rotation. The soil solid phase in the continuous cropping was 6.69% higher than that in rotation, and the liquid phases was 3.03%, while gas phases was 9.72% lower than that in rotation. The yield of rotation was 11.99 t/hm^2 higher than that of the continuous, reaching a significant level of 0.05. The changes of microbial community in the soil and the solid, liquid and gas phase of the soil were closely related to the continuous cropping obstacles of cassava. It is an effective way to overcome the continuous cropping obstacles of cassava to adopt cultivation management measures to adjust the composition of soil micro-organisms.