Coordinated Regulation Of Intercrop Combining Biological Medicament On The Structure And Function Of Biological System

Using chemical pesticide is the main cause that leads the soil pollution in Dangshan pear orchard.C hinese P.chinensis has a serious threat to the production and quality of pears.Nymphae of P.chinensis can live under the protection of its own secretion.The pesticide is hard to reach and kill them.Furthermore,nymphae can make resistance to any kinds of pesticides.We investigate the occurring rules of P.chinensisand predators on different types of pear,which aims to select the efficient biological medicament in 2012.In2013 and 2014,the manipulating experiment was established in pear orchard.The synergistic manipulation of pear intercropping Trifolium.repens and Platycodon grandiflorum combining with the biological agent on the population dynamics of P.chinensis and their predators was determined systematically andtests systematically the spatial and temporal distribution of chemical pesticide’s residue and estimates quantitatively the regulating effect of the combination of intercropping and biology medicament on physicochemical characters of soil and residue of pesticide in pear orchard.We set three treatments:(1)Intercropping Trifolium Repens+bio-organic fertilizer substitutes 20% of amount of routine using chemical germicide + SVAVONA substitutes 50% of amount of routine using chemical pesticide+ Phenazino-1-carboxylic acid substitutes 50% of amount of routine using chemical pesticide.(2)Intercropping Platycodon grandiflorum + bio-organic fertilizer substitutes 20% of amount of routine using chemical germicide + SVAVONA substitutes 50% of amount of routine using chemical pestic ide + Phenazino-1-carboxylic acid substitutes 50% of amount of routine using chemical pesticide.(3)Compare: chemical weeding + regular fertilization + regular using pesticide + regular using chemical germicide.The 2years experimental results showed that the total population size of predators in the areas of intercropping T.repens and P.grandiflorum were higher than in the bare area by artificial weeding.In 2013,the predator of dominant species was O.minutes in the areaof intercropping T.repens and P.fuscipes in the area of intercropping P.grandiflorum.In 2014,E.graminicolum and T.chinensis dominated in the areaof intercropping T.repens,H.axyridis,P.japonica,E.balteata and E.graminicolum dominated in the area of intercropping P.grandiflorum.In 2013,the nymphae of P.chinensi in the areas of both intercropping T.repens and P.grandiflorum combining with the biological agent on June 18 were significantly higher and on other dates were not significant difference compared with the bare area with conventional pesticide application.In 2014,the population densities of both adults and nymphae of P.chinensis were significantly lower in the areas of both intercropping T.repens and P.grandiflorum combining with the biological agent than in the bare area with conventional pesticide application during all the period of P.chinensis occurence.This research demonstrated that the measure of intercropping perennial T.repens and P.grandiflorum in pear orchard one year later combining with application of the biological agent SOVONA can substitute half of chemical pesticide usage.We tested main chemical pesticide’s detectable rate and residue in 0-20 cm,20-40 cm and 40-60 cm soil depth.The result show: the main chemical pesticide’s detectable rate and residue is: 0-20cm>20-40cm>40-60 cm,autumn>spring,which shows the soil chemical pesticide pollution is mainly from chemical medicament of current season.Through 2 years coordinated control experiment,the soil chemical pesticide residue of difenoconazole in treatment(1)and(2)is 5.67ppb、17.00 ppb separately,which is significantly lower than the compare 57.67 ppb.C hlorpyrifos is 2ppb and 3ppb separately,which is significantly lower than the compare 4 ppb.Imidacloprid is 180.00 ppb and 103.33 ppb separately,whic h is significantly lower than the compare 401.67 ppb.Platycodon grandiflorum has a significant effect on assimilating N itrogen in soil.Trifolium Repens has a significant effect on N itrogen fixation in soil.Platycodon grandiflorum and Trifolium Repens have a apparent effect on intercepting phosphorus in soil.The water content of soil that tested in sunny day is significantly higher than treatment(1)and(2).The temperature of soil surface tested at 12:30 on July 27 t h in treatment(1)and(2)is significantly lower than the area of manual weeding.