Effects Of Mechanical Harvesting On Soil Microbial Communities And Enzyme Activities In Sugarcane Rhizosphere

In this experiment,two sugarcane varieties were used to conduct on field test in Liaoping farm of Binyang,Nanning.The effects of mechanical harvesting on sugarcane ratoon growth,agronomic and yield traits,physical and chemical properties of soil,rhizosphere soil invertase activity and rhizosphere microbial community structure in different varieties and different periods were investigated.The main results were as followed:1.The roller compaction of different varieties of sugarcane increased soil bulk density and soil water content,but the difference reduced after the cultivator.The content of available nitrogen decreased,but the variation of available phosphorus and available potassium were related to the varieties.Mechanical harvesting reduced the number of sprouting and tillering,but had no significant effect on the plant height,stem diameter,cane yield and sucrose content.The studies showed that the effect on the growth of sugarcane ratoon in different varieties under the condition of mechanical harvesting of mechanical harvesting is not obvious.2.To some extent,the mechanical harvest of sugarcane increased the invertase activity in rhizosphere soil and decreased the urease activity in rhizosphere soil.But with the growth of sugarcane and cultivator,the difference between the two treatments and soil enzyme activity is not significant.3.Chao 1 index and ACE index analyses indicated that sugarcane harvesting treatment could improve the fungal species richness,but in different periods the richness and variety have different performance.Shannon diversity index analyses indicated that sugarcane harvesting treatment could improve the fungal diversity,but in different periods the bacterial species were different.High-throughput data analyses indicated there was an obviously dynamic change in the rhizosphere soil microbial community of sugarcane in different treatments at different stages.Fungal community at the Phylum level,Ascomycota,Unknown and Basidiomycota were two dominant groups.Redundancy analyses showed that the major fungal groups were affected by the soil pH and alkali hydrolyzable nitrogen of soil.The available phosphorus and alkali hydrolyzable nitrogen of soil were important factors affecting the composition of bacterial community.