Effects Of Nitrogen On Growth And Rhizosphere Soil Enzyme And Bacterial Community Of Panax Ginseng

The experiment was aimed to investigate the effects of different nitrogen consistence on the ginseng's growth and the change of soil enzymes and bacterial community of rhizosphere soil of ginseng in different period of growth on the farm Land of soil inprovement.There were four different nitrogen gradients including blank control(0?5?10?15 g/m2).The results were summarized as follows:1.The addition of moderate concentration of nitrogen(10g/m2)was appropriate considering the effects of different nitrogen consistence on the growth index on ginseng with the physical and chemical property of improved soils which total nitrogen were 3.13±0.65g/kg,available nitrogen 113±3.1mg/kg,available P 45.47±1.6mg/kg,available K 257.19±4.2mg/kg,organic matter 66.80±1.54g/kg,pH5.63±0.46 under this experimental condition.2.The effects of different nitrogen consistence on the ginseng's growth were presented as follows: The height of ginseng in the florescence and red fruit period were significantly enhanced with the moderate and high nitrogen consistence.The application of nitrogen did not significantly affect the height and stem diameter of ginseng in the budding time.Moderate nitrogen consistence can significantly enhance the stem diameter of ginseng in the florescence period.Moderate and high nitrogen consistence can significantly enhance the stem diameter of ginseng in the red fruit period and leaf areas of ginseng.The seedling survival rate of ginseng increased with the increase of nitrogen consistence,but there was no significant difference(P<0.05)between the treatments.3.The effects of different nitrogen consistence on the activities of four enzymes in rhizosphere soil of ginseng were as follows:There was no significant effect on the activity of catalase in rhizosphere soil in the florescence and red fruit period but the activity of catalase can significantly improved in the budding period of moderate nitrogen period.The activities of urease in the budding time and red fruit time and invertase in the budding,florescence and red fruit time were significantly enhanced in the moderate and high nitrogen concentration treatment.The high nitrogen consistence can significantly improve the activities of the ACP of rhizosphere soil in the budding and florescence period and urease in the red fruit period.The effects of different nitrogen consistence on the bacterial community of rhizosphere soil of ginseng were as follows:The results with the bacterial alpha diversity analyze in the rhizosphere soil showed that:There were no significant differences between ace,chao and shannon in different periods and treatments.The diversity of bacterial alpha was decreased in the budding time with the applications of nitrogen.In the red fruit period,using nitrogen can increase the bacterial alpha diversity in the rhizosphere soil,but the changing trend had no definite relationship with the application of nitrogen consistence.There was no significant effect in the diversity of bacteria in the rhizosphere soil between the different treatments.The findings of analysis of the components of the bacteriophyta levels in the rhizosphere soil of ginseng were as follows:The high concentration of nitrogen treatment can significantly increase the proportion of acidobacteria and increase with the increasing of nitrogen concentration,decreasing the contents of actinobacteria,Chloroflexi and Verrucomicrobia in the ginseng budding stage.The application of nitrogen decreased the contents of Gemmatimonasonadetes and bacillus in the rhizosphere soil of ginseng in the florescence period.In the red fruit period,the application of the nitrogen decreased the content of Verrucomicrobia,Gemmatimonasonadetes,Firmicutes and the content of the Verrucomicrobia increased with the decreasing of nitrogen consistence.Nitrogen treatment increased the contents of actinobacteria and Chloroflexi in the rhizosphere soil of ginseng.Nitrogen fertilization reduced the contents of actinobacteria,Gemmatimonasonadetes and Firmicutes and increased the contents of Verrucomicrobia in the rhizosphere soil of ginseng in the wilting stage.The study on the RDA analysis of bactetia at different stages in the rhizosphere soil of ginseng showed that: the contents of Candidatus Solibacter,Sphingomonas,Gemmatimonas,Nitrospira,Acidothermus were positively correlated with the set nitrogen concentration.The contents of Bradyrhizobium,Massilia,Clostridium sensu stricto 1,Methanosarcina were negatively correlated with nitrogen concentration.In the florescence period,the contents of the Gemmatimonas,Bradyrhizobium,Arthrobacter were positively correlated with the set nitrogen concentration and the contents of Nitrospira,Sphingomonas,Bryobacter,Rhizomicrobium,Pseudolabrys,Candidatus Solibacter were negatively correlated.In the red fruit period,the contents of the Nitrospira,Acidothermus and Gaiella were positively correlated with the set nitrogen concentration and the contents of the Candidatus Solibacter,Sphingomonas,Pseudolabrys,Bradyrhizobium,Bryobacter,Gemmatimonas,Rhodanobacter and Rhizomicrobium were negatively correlated.In the withering period,the contents of Arthrobacter and Bryobacter were positively correlated with the set nitrogen concentration and the contents of the Sphingomonas,Gemmatimonas,Candidatus Solibacter,Gaiella? Rhizomicrobium,Acidothermus,Bradyrhizobium,Rhodanobacter,Pseudolabrys and Nitrospira were negatively correlated.The results on the LefSe analysis of bactetia at different stages in the rhizosphere soil of ginseng showed as follows:In the budding time,the contents of Variibacter,Acetobacteraceae and Granulicell were significantly increased and the contents of Mycobacterium and Tumebacillus were significantly decrease with the nitrogen treatment,and the the content of Acetobacteraceae were increased with the increasing of the nitrogen concentration.In the florescence period,the contents of bacterium Ellin6517,Aquincola and Sorangium were significantly reduced in the rhizosphere soil of ginseng with the treatment of nitrogen,and the content of Sorangium were decreased with the increasing of nitrogen concentration.In the red fruit period,the treatment of nitrogen can significantly reduce the content of Acetobacteraceae and increase the content of Aquicella,Nocardioides,Haliangium,Actinoplanes and Planctomycetaceae in the rhizosphere soil of ginsengIncluding the content of Aquicella,Nocardioides and Actinoplanes increased with the increasing of the nitrogen concentration in the rhizosphere soil of ginseng.In the withering period,the contents of Myxococcaceae,Clostridium sensu stricto 12,Arthrobacter,Gemmatimonas,Streptomyces and Reyranella were significantly decreased with the treatment of nitrogen.The content of the Myxococcaceae was increased with the decreasing of the nitrogen concentration.The contents of the Anaeromyxobacter and Acidobacteriaceae can significantly increased and the content of Acidobacteriaceae increased with the increasing of the nitrogen concentration in the rhizosphere soil of ginseng with the treatment of nitrogen.