Impact Of Panax Notoginsong Continuous Cropping On Soil Enzyme Activity And Soil Chemical Properties

Panax notoginseng be known at home and abroad.Because of the increasing of repeating cultivation,and the unreasonable medication and fertilization,especially increasing the concentration of NPK and calcium magnesium phosphate?CaMgP?.Rsulted in the cotent of soil bulk density,acidity and heavy metal increased,resulting in soil nutrient imbalance,but also affect the response of soil enzyme,affect the normal growth of plant.In order to solve this problem,many studies have found that biochar and bio-bacterial manure can provide some nutrients for plant growth.And bio-bacterial manure has bio-control effect.And have results showed that the crop rotation or appropriate intervals can effectively reduce the incidence of plants.Focused on the influence factor and biological reduction of continuous cropping in P.notoginseng by positioning monitoring soil enzyme activity and soil chemical properties of which CaMgP and urease inhibitor fertilization,continuous cropping of P.notoginseng,different intervals after continuous cropping,the healthy plants and root rot of P.notoginseng.And compare the content of soil chemical properties and enzyme activity with the continuous cropping,find out the similarities and differences of soil chemical properties and enzyme activity between continuous cropping and new soil which fertilize CaMgP and urease inhibitor.From the soil enzyme activity,the content of soil chemical properties and its interaction effects,to research the relationship among soil nutrient,enzyme activity and soil-borne diseases of P.notoginseng.And analyze the effect of continuous cropping on the expression of disease-resistant gene related to root rot.To explore the method of biological reduction about continuous cropping in P.notoginseng and to achieve ecological cultivation to provide a scientific basis and new prevention strategies.The results showed that:?1?The seedling rate and survival rate were decreased,and the incidence of root rot was increased after continuous cropping of P.notoginseng.New soil increasing CaMgP and urease inhibitor?nBPT,N-butyl phosphorothioatetriamine?were also reduced the seedling rate and survival rate,and CaMgP was increased the incidence of root rot.After continuous cropping,interval more than three years can effectively improve the seedling rate and survival rate,reduce the incidence of root rot.Indicating that continuous cropping and irrational use of CaMgP and nBPT will affect the growth of P.notoginseng and the expression of disease-resistant gene related to root rot.So we can reduce the impact of continuous cropping on the growthe of P.notoginseng by the appropriate interval.?2?The activities of catalase?H₂O₂?,urease and neutral phosphatase in soil were decreased,while the activities of invertase and polyphenol oxidase?PPO?were increased after continuous cropping and root rot of P.notoginseng.New soil increasing CaMgP was also reduced the activities of soil neutral phosphatase,urease and H₂O₂,and addition of nBPT can significantly inhibit the activity of urease.The activities of soil neutral phosphatase,urease and catalase were increased at interval 1 year,3 years and 5 years after continuous cropping,and the activities of sucrose and PPO were decreased.The result showed that the continuous cropping of P.notoginseng was mainly related to the decrease of H₂O₂,urease and phosphatase activities and the increase of sucrose and PPO.?3?The contents of pH,NH₄⁺-N,NO₃^--N,available P and total N in soil were decrased,while the contents of Ca²⁺,Mg²⁺,HCO₃^-and total P were increased after continuous cropping of P.notoginseng.And the contents of NH₄⁺-N,NO₃^--N,available P and total N were decreased after infection of root rot,while the contents of pH,Ca²⁺,Mg²⁺,HCO₃^-and available K were increased.Addition of CaMgP and nBPT can increased the contents of pH,HCO₃^-and available P in the soil,and decreased the contents of NH₄⁺-N and NO₃^--N.The contents of pH,NH₄⁺-N,NO₃^--N,available P and total N were increased at interval 1 year,3 years and 5 years after continuous cropping,and the Ca²⁺,Mg²⁺ and HCO₃^-concentrations were decreased.Correlation analysis of soil enzyme activity,soil nutrient and the growth of P.notoginseng was carried out.Soil nutrient have significantly correlated with soil enzymeactivity,and have significantly correlated with survival rate and incidence of root rot of P.notoginseng.And siol enzyme activity affects the growth of P.notoginseng by affecting siol nutrient.It can be seen that the continuous cropping of P.notoginseng is related to the change of soil nutrient.?4?From the above results,the appropriate interval of continuous cropping of P.notoginseng can effectively reduce the obstacle of continuous cropping.The unreasonable application of CaMgP can affect the balance of soil enzyme and nutrient,and will inhibit the growth of P.notoginseng.Therefore,the study uses biochar and Burkholderia to reduce the obstacle of continuous cropping.It was found that biochar and biochar combination with Burkholderia could improve the seedling rate and survival rate of P.notoginseng,and could reduce the incidence of root rot.And biochar combination with bio-bacterial manure can significantly improve the activity of urease,phosphatase and invertase.The result showed that biochar combination with bio-bacterial manure can effectively reduce the continuous cropping of P.notoginseng.