Influence of mechanized cultivation on sugarcane/potato intercropping in soil microbial diversity and nutrient absorption of sugarcane

【Objective】To investigate the influence on soil microbial diversity and sugarcane nutrient accumulation by mechanized cultivation of sugarcane/potato intercropping.Furthermore, to provide scientific evidence for the application and promotion of this cultivated mode.【Method】A field randomized block experiment which including two treatments:sugarcane monoculture(control) and sugarcane/potato intercropping was set up.The rhizosphere and non-rhizosphere soil of each treatment were collected for further analysis, which were rhizosphere soil of sugarcane monoculture, non-rhizosphere soil of sugarcane monoculture, rhizosphere soil of sugarcane intercropping and non-rhizosphere soil of sugarcane intercropping.The physical and chemical properties difference, nutrient accumulation in sugarcane plant and microbial community structure diversity in soil in different treatments were analyzed using traditional measurement and Illumina high throughput sequencing technology.【Result】As compared to the monoculture, the organic matter content, hydrolysable nitrogen, available phosphorus and available potassium contents in rhizosphere soil of sugarcane cropping were significantly increased by 4.93%, 12.32%, 6.40% and 8.92% (P< 0.05, the same below), while those in non-rhizosphere soil were increased by 10.50%, 56.01%, 48.31% and 51.52%, respectively.The soil bulk density was significantly reduced while soil water content was increased in intercropping area.The Shannon, ACE and Chao1 indexes of fungus in intercropping soil were significantly higher than monoculture.But the Simpson index was significantly lower than monoculture.The Shannon, Simpson, ACE and Chao1 indexes of bacteria in intercropping soil had no significant difference with monoculture(P> 0.05, the same below).Intercropping increased the proportion of Acidobacteria, Chloroflexi and Planctomycetes in bacteria and Basidiomycota, Mucoromycota and other unknown fungi, and decreased the proportion of Proteobacteria, Actinobacteria, Firmicutes and Patescibacteria in bacteria and Ascomycota in fungus.The relative abundance of Acidobacteria, Chlorobacteria and Lycophyta in bacteria, and unknown fungi were increased in intercropping than monoculture, but those of Acidobacteria and Firmicutes in bacteria, Saccharomyces in fungi were decreased.Correlation analysis indicated that the soil pH, soil organic matter content, soil available potassium content, soil bulk density and soil water content had a great influence on soil microbial diversity.Among them, Bacteroidetes and Firmicutes diversity of soil bacterial had significant positive correlation with soil bulk density and available phosphorus content, while the diversity of Chloroflexi and Gemmatimonadetes were significantly negatively correlated with soil bulk density and available potassium content.As for the soil fungi diversity, Ascomycota was significantly positively correlated with soil bulk density while Basidiomycota was significantly negatively correlated with it.The nitrogen accumulation was significantly increased, but the phosphorus and potassium accumulation were decreased in sugarcane plant at seedling stage of intercropping treatment, while that was no significant difference of nutrient accumulation at the mature stage.【Conclusion】The mechanized cultivation of sugarcane/potato intercropping has a positively impact on soil chemical properties, changes soil microbial diversity, sugarcane production and sugar content, increase economic benefit and realize the combination of land use and maintenance.It is a reasonable interplanting mode.