Effects Of Interspecific Interactions On Apple And Trifolium N、P、K Contents And Nutrient Accumulation In Apple/White Clover Compound System

Orchard cultivation is the orchard soil management model commonly used in developed countries in the world.The country also promoted the technical measures in the country in1998.In this experiment,white clover(Trifolium repens L.)and apples(Malus demestica Borkh.)were used as test materials.Through combination of root box cultivation test and indoor analysis,it was studied that the interactions between different species of apple growth and development were different for the white clover and apple components in the apple/white clover composite system.The contents of N,P and K in the organs and their accumulation and distribution patterns were to provide theoretical basis for further revealing the interspecific interaction mechanism and the management of orchard weeds.The main research results are as follows:(1)During the entire growth and development period,the interspecific interactions inhibited the growth and development of the apple components in the composite system,and the aboveground biomass decreased by 19.23%,24.84%,and 33.54% in the spring shoot stage,fall shoot stage,and defoliation stage,respectively.Root biomass decreased by 35.96%and 22.25% in spring shoot period and deciduous period,and increased by 15.12% in autumn.The growth of white clover was promoted,and the biomass of white clover leaves increased during the shoots of autumn and leaves.67.3% and 44.31% respectively,root biomass in the underground increased by 39.43% and 44.49% in autumn and deciduous periods,respectively;apple roots showed a downward trend throughout the growing season,and white clover roots were at the spring shoot stage.The deciduous period has a tendency to migrate to deeper soil layers.(2)The ratio of apple root to shoot in the composite system of autumn shoot stage and deciduous stage was improved.The ratio of apple root to crown was increased by 107.18%and 16.34%,respectively,compared with apple monocropping.However,the spring shoot stage was 32.71% lower than that of apple monocropping.The interspecific interactions reduced the ratio of root to crown of white clover in the compound system.The rate of the spring shoot stage and the fall shoot stage were reduced by 16.51% and 15.69%,respectively,compared with that of the monocropping system.In the defoliation stage,the ratio was increased by 3.39%.(3)During the whole growth and development period,the interspecific interaction effect reduced the element content of each component of the apple component in the composite system,the most obvious decrease in the fall shoot stage,and reduced the element content of each organ in the aboveground parts of the white clover.Increased root element content is most noticeable during fall shoots.(4)From the perspective of the entire growth and development period,the interaction between species reduced the accumulation of N,P,and K elements in the apple system in the compound system.The performance during the fall and deciduous stages was more pronounced,and the white system in the compound system was improved.The cumulative amounts of N,P,and K in the leaf fractions were more pronounced during autumn shoots,which mainly affected the cumulative amounts of N and P.The proportion of N,P,K accumulations in total shoots and perennial branches in apple shoots increased,and the proportion of N,P,K accumulations in total shoots increased in stems of white clover.The proportion of N elements in apple roots was higher in roots with diameters≤3mm than those in monoculture,and the percentage of P elements in roots with diameters≤2mm was higher than that in monoculture,and K was in diameter.The proportion of roots≥2mm was higher than that of monoculture,and the proportion of N,P and K elements in white clover rose in the root system of 0-20 cm.(5)The simulation results show that in the apple/white clover composite system,the accumulation of N,P in apple components decreases with the increase of the N,P accumulation of white clover components.In the spring shoot stage,the composite system The competitiveness of Chinese white trifoliate components for nutrients is lower than that of apple components,while in the fall shoot stage and deciduous stage,the white clover component competes more strongly for N and P elements than apple components for N.The competition between P and P elements was more obvious especially during the fall shoot period.At the same time,the competition ratio of white clover components to N was higher than that of P competition ratio.