Effects of Intercropping-rotation Planting Pattern of Flue-cured Tobacco and Sweet Potato on Communities of Soil Microorganisms and Nematode in Dryland of Western Henan Province

DU Jingshan; WANG Yujie; HE Bing; WEN Xuanlin; ZHANG Shuhao; HE Mengying; WANG Hui; GAO Jiakai; SHEN Hongtao; JIAO Nianyuan; WANG Yanfang; LIU Ling

doi:10.15926/j.cnki.issn1672-6871.2025.02.009

Abstract：To explore suitable planting patterns for the sustainable high-quality development of flue-cured tobacco in drylands of western Henan province,the field experiment and high-throughput sequencing technology were conducted using flue-cured tobacco'He Luo 1'and fresh-eating sweet potato'Pu Shu 32'.The effects of tobacco-tobacco continuous cropping(CK treatment)and tobacco-sweet potato intercropping-rotation(T treatment,two ridges of tobacco alternating with two ridges of sweet potato,alternating ridges every other year)on the structures and diversity of microbial and nematode communities in tobacco-planted soil were examined.The results show that compare with the CK treatment,the ACE index and Chao 1 index of soil bacterial communities significantly increase by 3.47％and 2.39％respectively under T treatment.The Chao 1 index of fungal communities significantly increase by 1.95％.The structure of soil microbial communities is shown to be different between T treatment.The relative abundances of bacterial Actinobacteriota and Acidobacteriota,along with fungal Ascomycota in T treatment increase by 2.49％,23.98％,and 19.14％respectively.Meanwhile,the relative abundances of bacterial Proteobacteria and Chloroflexi,together with fungal Basidiomycota,Mortierellomycota,and Chytridiomycota decrease by 11.52％,12.20％,48.21％,14.86％,and 12.23％respectively.The bacterial communities Hymenobacteraceae,Oxalobacteraceae and Adhaeribacter,as well as the fungal groups Sordariomycetes and Sordariales are significantly enriched in T treatment.Acrobeloides is the common dominant nematode in different soil treatments,and the dominant trophic groups are bacterivorous nematode.The relative abundances of bacterivorous nematode,plant-parasitic nematodes,and omnivore/predator nematode are reduced,and the relative abundance of fungivorous nematode is increased by T treatment.The soil organic matter decomposition pathway is mainly mediated through bacterial channels.Compare with the CK treatment,the nematode diversity and abundance reduce by 45.38％and 69.62％respectively,and the structure Index increase by 130.79％and the enrichment index enhance by 6 892.31％under T treatment.The tobacco-sweet potato intercropping-rotation is beneficial for increase soil microbial community richness,improve the microbial community structure,and increase the proportion of dominant bacterial populations.The stability of the nematode ecosystem is better,the connectivity and complexity of the soil food web are higher in tobacco-sweet potato intercropping-rotation and can provide favorable soil environments for tobacco production.