| Soil is the carrier of plant growth,which supplies the water and nutrients needed for plant growth;soil oxygen is also necessary for normal plant growth.Suitable soil structure and suitable solid,liquid and gas three-phase ratio can be more conducive to plant growth and development.In this study,apple seedlings and orchard apple trees were used as materials to investigate the effects of soil bulk density and root zone aeration on apple soil enzymes and microbes and seedling roots.The results showed that:1.With the increase of soil bulk density,the oxygen content in the root zone decreased gradually.The total root length,root surface area,root volume,root diameter,root tip number and root fractal dimension of the root weight treatment of 1.40g/cm~3 were significant.Higher than soil bulk density of 1.25g/cm~3 treatment and 1.55g/cm~3 treatment;suitable soil bulk density(1.40g/cm~3)can ensure root growth and maintain good root morphology;soil bulk density is too high(1.55g/cm~3)inhibited the normal growth of the roots of the sweet tea seedlings.2.Chemical aeration in the root zone under high soil bulk density(1.55g/cm~3)significantly increased the oxygen concentration in the root zone;total root length,root surface area,root diameter,root average diameter,root tip number and root fractal of the aerobic treatment The dimension was significantly higher than 1.55g/cm~3 without aeration treatment,and the indicators increased by 24.13%,40.42%,192.67%,40.10%,38.71%,and2.26%,respectively.The root zone aeration increased root activity and decreased The accumulation of root MDA content.3.Soil drilling and drilling of corn stover and apple branches in apple orchard for borehole aeration effectively increase oxygen content,oxygen diffusion rate,soil total organic carbon(TOC)content,soil cane sugar in orchard soil layers.Enzyme activity,soil urease activity and soil catalase activity.The improvement effect of the four treatments is from high to low,followed by drilling corn stalks,inserting apple branches,drilling backfill and not drilling.4.High-throughput sequencing of apple root zone soil showed that the bacteria in the apple root zone soil samples contained Proteobacteria,Chloroflexi,Actinobacteria,and Acidobacteria.),Gemmatimonadetes and other bacterial groups,the composition of bacterial communities in each treatment is similar;except for other fungi of unspecified species,Proteobacteria,Green Campylobacter,Actinobacteria and Acid Bacillus The relative abundance is the highest,25.6%-53.2%,7.1%-24.1%and 7.5%-20.2%,5.8%-21.1%,which are dominant bacteria;the fungus in the apple root zone soil sample contains Basidiomycota,Ascomycota,Zygomycota,Chytridiomycota,Glomeromycota,etc.,in addition to other species of unidentified species,Basidiomycota,Ascomycetes Ascomycota has the highest relative abundance,which is 3.4%-19.6%,42.3%-81.8%,respectively,and is a dominant fungus.5.Drilling and drilling the root zone soil to insert corn stalks and apple branches to improve the bacterial community richness in 0-20cm,20-40cm and 40-60cm soils compared with non-drilling holes.Corn stalk(HCS)can effectively increase the bacterial and fungal community richness in 40-60 cm soil;borehole and bored corn stalk and apple branch treatment reduce soil bacterial diversity in 40-60 cm soil layer;From the perspective of the comprehensive effect of the environment,from high to low,the corn stalks are inserted into the boreholes,the apple branches are drilled,the boreholes are backfilled,and the boreholes are not drilled. |
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