Effects Of Grafting And Artificial Weeding On Soil Fertility And Health In Rhizosphere Of Star Anise Trees

At present,overusing of fertilizers and lacking of standardized management are still the important causes for resulting in low yield and quality of star anise in Guangxi,China.To explore the effects of different cultivation measures,particularly,grafting and artificial weeding on soil fertility and health in star anise plantations,soil biological properties and microbial community structure were analyzed in this paper.The conclusions are summarized as follows:1.In comparison with the soil in rhizosphere of primary(non-grafted)star anise trees,there was no significant difference with the activities of soil β-glucosidase in rhizospheres between grafted and primary star anise trees.However,the activity of aminopeptidase was significantly lower.And the activity of phosphatase was significantly higher than those of primary star anise trees.Moreover,except of soil microbial biomass nitrogen,there was no significant difference between each other,soil microbial biomass carbon and phosphorus were all significantly lower than those of primary star anise trees too.It indicated that the availability of soil phosphorus in rhizosphere of star anise trees could be improved by grafting.2.In comparison with the soil in rhizosphere of primary star anise trees,soil bacterial richness in rhizosphere could be significantly improved by grafting.Meanwhile,Bacteroidetes was the soil dominant bacterial phylum in rhizosphere of grafted star anise trees and Firmicutes was the soil dominant bacterial phylum in rhizosphere of primary star anise trees.Furthermore,norank＿c＿＿TK10,Diplorickettsiales,norank＿c＿＿Subgroup＿6,B12-WMSP1 and Pedosphaerales were the soil dominant bacterial orders in rhizosphere of grafted star anise trees.And Bacillales and norank＿c＿＿Actinobacteria were the soil dominant bacterial orders in rhizosphere of primary star anise trees.norank＿o＿＿norank＿c＿＿TK10,Polyangiaceae,Diplorickettsiaceae,norank＿o＿＿norank＿c＿＿Subgroup＿6 and Pedosphaeraceae were the soil dominant bacterial families in rhizosphere of grafted star anise trees.On the contrary Xiphinematobacteraceae,Mycobacteriaceae and norank＿o＿＿norank＿c＿＿Actinobacteriaand were the soil dominant bacterial families in rhizospheres of primary star anise trees.Moreover,unclassified＿f＿＿Ktedonobacteraceae,FCPS473,1921-2,norank＿f＿＿norank＿o＿＿norank＿c＿＿Subgroup＿6,norank＿f＿＿norank＿o＿＿B12-WMSP1,norank＿f＿＿norank＿o＿＿norank＿c＿＿TK10,Pajaroellobacter,norank＿f＿＿norank＿o＿＿norank＿c＿＿Subgroup＿6 and Pajaroellobacter,etc were the soil dominant bacterial genera in rhizosphere of graftedstar anise trees.By contrast,Candidatus＿Xiphinematobacter,Mycobacterium,and norank＿f＿＿norank＿o＿＿norank＿c＿＿Actinobacteria were the soil dominant bacterial genera in rhizosphere of primary star anise trees.3.In comparison with the soil in rhizosphere of primary star anise trees,soil fungal richness in rhizosphere also could be significantly increased by grafting.Among them,Rozellomycota,soil dominant fungal phylum,Trichosporonales,GS11,Helotiales,Chaetosphaeriales and Sordariales,soil dominant fungal orders,Trichosporonaceae,unclassified＿o＿＿GS11,Hypocreaceae,Clavicipitaceae,Chaetosphaeriaceae and Chaetomiaceae,soil dominant fungal families and Apiotrichum,Penicillium,unclassified＿o＿＿GS11,Trichoderma and unclassified＿f＿＿Clavicipitaceae were the soil dominant fungal genera in rhizosphere of grafted star anise trees,respectively.4.In addition,although the activity of β-glucosidase in soil was not significantly different between manual weeding and no-weeding star anise plantations,but the activities of aminopeptidase and phosphatase were significantly lower and higher in soil of weeding treatment which compared to no-weeding treatment,respectively.Furthermore,in comparison with no-weeding treatment,soil microbial biomass carbon and nitrogen were all significantly higher than those of noweeding treatment.However,soil microbial biomass phosphorus significantly decreased in soil of weeding treatment.It indicated that the cycling of soil phosphorus could be significantly improved and the pools of soil carbon and nitrogen could be significantly stored in star anise plantations by manual weeding.In one word,soil fertility in star anise plantations can be promoted by manual weeding.5.In comparison with no weeding star anise plantation,although soil bacterial diversity and abundance were not significantly altered by manual weeding,but Bacteroidetes enriched as the soil special dominant bacterial phylum in star anise plantation under manual weeding.By contrast,Bacillales,norank＿c＿＿Subgroup＿6 and B12-WMSP1,the soil unique bacterial orders,norank＿o＿＿norank＿c＿＿Subgroup＿6,Beijerinckiaceae and norank＿o＿＿B12-WMSP1,the soil unique bacterial families and norank＿f＿＿norank＿o＿＿norank＿c＿＿subgroup＿6,norank＿f＿＿norank＿o＿＿B12-WMSP1 and 1921-2 were the soil special dominant bacterial genera in star anise plantation without weeding,respectively.6.In comparison with no weeding star anise plantation,although soil fungal diversity and abundance were not significantly altered,but the proportions of some dominant fungal phyla changed by manual weeding.For example,Basidiomycota,its proportions with 26.71% in no-weeding plantation were sharply increased to 34.96% by manual weeding.Moreover,not only the fungal orders of Mortierellales,Helotiales and Sordariales,and the families of Clavicipitaceae,Mortierellaceae and Chaetomiaceae lost,but also the soil fungal genera of unclassified＿f＿＿Clavicipitaceae and Mortierella lost by manual weeding.In summary,the availability of soil phosphorus in rhizosphere of star anise trees can be improved by grafting.Furthermore,although soil microbial diversity can not be promoted,but soil microbial richness in rhizospheres of star anise trees can be significantly improved by grafting.Moreover,soil unique dominant microbes at different levels also enriched in rhizospheres of grafted star anise trees.It suggests that soil health in rhizosphere---the microenvironment of star anise trees can be maintained by grafting.In addition,soil microbial biomass carbon and nitrogen,the availability of soil phosphorus,i.e.,soil fertility in star anise plantation can be significantly improved,by manual weeding.Meanwhile,even though soil microbial diversity and richness can not be significantly improved by manual weeding,but the compositions and proportions of some dominant microbes can be altered by manual weeding.In one word,soil fertility and health in star anise plantations not only do not decrease,but also can be improved by grafting or manual weeding.