Effects Of Mixed Planting Of Three Kinds Of Crops And Replanted Young Apple Trees On The Growth Of Aeplanted Apple Tree And Soil Environment

The experiment was carried out with soil from 31-year-old apple orchard in Manzhuang Town,Tai’an City,Shandong Province,and Two-year-old tobacco rich 3/T337 as test material.the following treatments were performed: the control of old apple orchard soil(CK),the methyl bromide fumigation old apple orchard soil(T1),grafted apple seedlings mixed with Allium fistulosum(T2),grafted apple seedlings mixed with Triticum aestivum(T3),grafted apple seedlings mixed with Brassica juncea(T4).The effects of mixed planting of different crops on the environment of continuous cropping soil and the replanting of young apple trees were studied for two years(2016-2018).The results were as follows:1.Compared with the old apple orchard soil,mixed the three kinds of crops and young apple tree obviously enhanced the young apple biomass,which was shown as follows: the methyl bromide fumigation old apple orchard soil > grafted apple seedlings mixed with Allium fistulosum > grafted apple seedlings mixed with Triticum aestivum >grafted apple seedlings mixed with Brassica juncea > the old apple orchard soil.The results of 2016 showed that the plant height,ground diameter,fresh weight,dry weight,average fresh shoot length,and total fresh shoot length of young apple trees treated with the methyl bromide sterilization treatment were 1.14,1.35,2.43,2.35,1.43 and 6.97 times of the control,respectively,and The grafted apple seedlings mixed with Allium fistulosum treatment was1.12,1.31,1.71,1.65,1.25 and 2.09 times of the control,respectively,and The grafted apple seedlings mixed with Triticum aestivum treatment was 1.04,1.22,1.43,1.41,1.14 and 1.91 times of the control,respectively,and The grafted apple seedlings mixed with Brassica juncea treatment was 1.10,1.29,1.48,1.59,1.12 and 1.88 times of the control,respectively.2.The results of two years showed that compared with the old apple orchard soil,the grafted apple young trees were mixed with Allium fistulosum,Triticum aestivum and Brassica junceaonion,the enzyme activity of soil was increased.Compared with CK,the urease activity of T2(the grafted apple young trees were mixed with Allium fistulosum)increased by31.80% and 22.81%,respectively,and the phosphatase activity increased by 35.13% and20.91 %,respectively,and the surcease activity increased by 11.96% and 53.26%,respectively;the urease activity of T3(the grafted apple young trees were mixed withTriticum aestivum)increased by 24.92% and 14.69%,respectively,and the phosphatase activity increased by 59.26% and 54.16%,respectively,and the surcease activity increased by50.37% and 53.26%,respectively;the urease activity of T4(the grafted apple young trees were mixed with Brassica juncea)increased by 44.59% and 36.56%,respectively,and the phosphatase activity increased by 37.67% and 66.12%,respectively,and the surcease activity increased by 34.31% and 31.52%,respectively;the urease activity of T1(the methyl bromide fumigation old apple orchard soil)reduced by 26.56% and 25.00%,respectively,and the phosphatase activity reduced by 30.07% and 95%,respectively,and the surcease activity reduced by 30.57% and 29.35%,respectively;As a whole,The methyl bromide fumigation inhibits the activity soil enzyme.3.The results of two years showed that compared with the old apple orchard soil,mixed planting three crops could increase the number of soil bacteria and actinomycetes,and reduce the number of soil fungi.Compared with the control,the number of soil fungi with the methyl bromide fumigation sterilization reduced by 81.33% and 93.10%,respectively,the number of soil bacteria decreased by 50.00% and 21.95%,respectively,and the number of soil actinomycetes decreased by 32.00% and 41.45%,respectively;the number of soil bacteria increased by 37.93% and 293.70 %,respectively,and the number of soil fungi reduced by41.33% and 60.34%,respectively,and the number of soil actinomycetes increased by 40.00%and 33.84%,respectively,under the treatment of mixed planting with A.fistulosum;the number of soil fungi reduced by decreased 42.67% and 55.17%,respectively,and the number of soil bacteria increased by 31.03% and 189.12%,respectively,and the number of soil actinomycetes increased by 48.00% and 33.84 %,respectively,under the treatment of mixed T.aestivum;the number of soil fungi reduced by decreased 40.00% and 48.28%,respectively,and the number of soil bacteria increased by 13.79% and 141.41%,respectively,and the number of soil actinomycetes increased by 52.00% and 27.63%,respectively,under the treatment of mixed B.juncea.The ratio of bacteria to fungus in the soil for two years was shown as follows: the methyl bromide fumigation old apple orchard soil > grafted apple seedlings mixed with Allium fistulosum > grafted apple seedlings mixed with Brassica juncea > grafted apple seedlings mixed with Triticum aestivum > the old apple orchard soil.4.The content of phlorzin in mixed planting A.fistulosum,T.aestivumcrops and B.juncea soil decreased by 81.23%,20.56% and 86.11%,respectively,Compared with CK,the content of Catechins,Coumaricacid,Vanillin,Ferulic acid,phlorzin and Caffeic acid significantly reduced under the treatment of mixed planting with A.fistulosum;the totalamount of phenolic acid in the soil of the mixed planting of A.fistulosum decreased by28.27%,and the effect was better than other treatments.5.The quantitative analysis of real-time fluorescence quantitative PCR showed that the gene copy number of Fusarium genus in the mixed three kinds of crops was lower than that of control,and showed significant differences.The gene copy number of F.moniliforme,F.oxysporum,F.solani and F.proliferatum declined by 61.01%,37.11%,40.97% and 53.11%under the treatment of mixed planting with A.fistulosum,respectively.The gene copy number of F.moniliforme,F.oxysporum,F.solani and F.proliferatum declined by 37.74%,5.11%,41.70% and 18.30% under the treatment of mixed planting with Triticum aestivum,respectively,The gene copy number of F.moniliforme,F.oxysporum,F.solani and F.proliferatum declined by 57.23%,35.34%,29.68% and 61.47% under the treatment of mixed planting with Brassica juncea,respectively,The gene copy number of F.moniliforme,F.oxysporum,F.solani and F.proliferatum declined by 68.55%,48.11%,62.88% and 68.67%under the treatment of the methyl bromide fumigation,respectively.