Effect Of Glyphosate And Abamectin On Nitrogen And Phosphorus Activation Of Ceriporia Lacerata HG2011

Nitrogen and phosphorus are essential nutrients for plant growth and development,but N mainly exists in organic form in soil,and P mostly exists in insoluble inorganic phosphate and organic phosphorus,which is difficult to be absorbed and utilized directly by plants.Therefore,the application of chemical fertilizer is one of the important measures to improve crop yield and quality in agricultural production.However,long-term and large-scale application of chemical fertilizers has resulted in a series of production and environmental problems,such as the non-equilibrium accumulation of soil nutrients,the reduction of fertilizer utilization rate,the change of soil microbial population,and environmental pollution.In addition,chemical pesticides are commonly used to control crop diseases,pests and weeds.Soil N and P availability and fertilizer use efficiency could be improved by microorganism participating in soil N and P activation.It is necessary to study the effect of Chemical Pesticides on the function of microbial inoculants because of the inevitable interaction between chemical pesticides and microbial inoculants in crop nutrient management.The aim of this study was to investigate the effects of glyphosate and Abamectin on the growth and nitrogen and phosphorus activation of Ceriporia lacerata HG2011,it provides useful information for the scientific application of chemical pesticides and microbial inoculants.The main results are as follows:1.In the experiment of solid culture,glyphosate and Abamectin inhibited HG2011 growth,the higher the concentration of pesticide,the more obvious the inhibitory effect.The semi-inhibitory concentrations of glyphosate and Abamectin on the bacteria were 3.73 mg/m L and 111.32 mg/kg,which were significantly lower than the application concentrations.2.In the experiment of liquid culture,The effect of two pesticides on the growth of HG2011 was similar to solid culture.Pesticides affect nitrogen and phosphorus activation through inhibiting secretion of protease,phosphatase,protons,or organic acids.In addition,low concentrations of glyphosate promoted HG2011 growth,N and P activation,while low concentrations of Abamectin did not.High concentrations of glyphosate and Abamectin significantly inhibited HG2011 growth,N and P activation.3.In the experiment of soil culture,HG2011 was inoculated on the sterilized soil surface,the content of ammonium nitrogen and soluble phosphorus in the soil increased,the p H decreased,and the protease,phosphatase and microbial biomass nitrogen and phosphorus was detected,the results showed that HG2011 grew on soil surface and in soil,and secreted protease,phosphatase,proton or organic acid to activate soil nitrogen and phosphorus.The effect of glyphosate on the activation of HG2011 was dose-dependent.The higher the concentration,the stronger the inhibition.The correlation analysis showed that the activity of protease was positively correlated with the content of ammonium N(r = 0.929,n = 16,P < 0.01),and the activity of phosphatase was positively correlated with the content of available P(r = 0.918,n =16,P < 0.01),it was negatively correlated with p H(r =-0.957,n= 16,P < 0.01)4.In the pot experiment,HG2011 significantly promoted the growth and nutrients uptake of lettuce.Without the application of glyphosate,the biomass of lettuce was increased by 12.9% ～ 24.9% and the nutrient uptake was increased by4.92% ～ 38.21% after applying HG2011,With the application of glyphosate,the biomass of lettuce was increased by 10.7% ～ 23.1%,the nutrients uptake was increased by 2.94% ～ 34.74%.After applying HG2011,the activities of protease,phosphatase,microbial biomass nitrogen and microbial biomass phosphorus in the rhizosphere soil of lettuce increased significantly,however,the content of protease,phosphatase,microbial biomass nitrogen and microbial biomass phosphorus decreased after the application of glyphosate,which indicated that HG2011 could activate soil nutrients and promote lettuce growth,but glyphosate could affect the activation ability of HG2011.In a word,Glyphosate and Abamectin could inhibit the beneficial effects of HG2011 in activating soil nitrogen and phosphorus and promoting plant growth.In the course of application,the safety interval should be fully considered.