Effects Of Pulverized Branches Of Pear Trees Returning To The Field On Pear Orchard Soil And Growth Of The Tree

In order to explore the effect of winter pruning of pear tree waste branch return,so that its pruned branches can be resourced.This study conducted a pear tree shoot shattering and cover field experiment with‘Jinmi’pear from 2017 to 2018.A total of four treatments were set up in the experiment:no return field(0 kg·plant^-1,CK),low volume return field(4kg·plant^-1,T1),conventional volume return field(8 kg·plant^-1,T2)and high volume return field(12 Kg·plant^-1,T3),the effects of different treatments on mineral elements contents,soil microbial contents,soil enzyme activities,growth status of newly growing branches of pear trees,leaf growth status of pear trees,and quality of pear fruits were investigated.The results of this study show that:（1）The results showed that the content of OM（organic matter）,Mn（total manganese）,Fe（total iron）,Cu（total copper）,Zn（total zinc）,B（total boron）,Ca（total calcium）,Mg（total magnesium）,s（total sulfur）,TN（total nitrogen）,nitrate-N（nitrate nitrogen）,AK（available potassium）and OP（available phosphorus）in soil could be increased by adding conventional amount of crushed pear tree branches into soil,and the p H value of soil could be increased to improve soil acidification.At the same time,it can also increase the number of fungi and actinomycetes in soil and significantly improve the catalase activity.（2）The addition of a high amount of crushing pear tree branches to the soil caused a decrease in soil Mn and Zn contents,along with the inhibition of soil peroxidase activity,which in turn reduced soil fertility to some extent.Also,the addition of low amounts of crushed pear tree branches to the soil caused a significant decrease in the S,TP（total phosphorus）,and AP（fast acting phosphorus）contents.（3）Compared with CK branches mulching（T1～T3）had no significant effect on bacterial diversity,but increased the relative abundance of Proteobacteria,and decreased Chloroflexi.Branches mulching altered the bacterial community structures at order level.For the fungi,R4 treatment had the highest chao1 index.At fungal phylum level,branches mulching（T1～T3）increased the relative abundance of Basidiomycota,but decreased the relative abundance of Ascomycota.At fungal order level,branches mulching increased the relative abundance of the relative abundance Agaricales and Sordariales,but decreased Microascales.（4）Application of a regular amount of crushed pear tree branches to the soil resulted in a significant increase in the Fe,Zn,Ca,and TN（total nitrogen）contents of the soil.It also significantly increased the individual fruit weight,the aspect longitude,and Vc content of the fruit,as well as fruit firmness,and significantly decreased the titratable acid content of the fruit,resulting in a significant improvement in fruit quality.Therefore,the current study recommended 8 kg·plant^-1 as the optimal shoot return in the short-term period under the conditions of current pear garden shoot shattering cover and return fields,which combines soil physicochemical properties,pear newly growing shoot growth,pear leaf growth,and pear fruit quality changes.