| As a large country in apple cultivation and production,there are still many problems in fertilization of orchards.At present,there are many studies on the excessive fertilizer,soil pollution and cost increase caused by fertilization of fruit trees by reducing the amount of chemical fertilizer,applying organic fertilizer or biological fertilizer,but there are relatively few studies on the combined application effect of microbial agents and different fertilizers.In this study,a total of 6 groups of compound fertilizer,organic fertilizer and microbial agent were applied in combination with 9-year-old red Fuji/M26 apple,and 6 groups of compound fertilizer(CK),farm manure(T1),compound fertilizer + farm fertilizer(T2),farm fertilizer +microbial agent(T3),compound fertilizer + farm fertilizer + microbial agent(T4),compound fertilizer + commercial organic fertilizer(T5)were used to determine the growth,results and quality of soil microorganisms and apples,in order to explore the microbial agents and organic,The method of combined application of inorganic fertilizer provides a basis for further improving the soil microenvironment,promoting tree growth and development,and improving fruit quality.The experiment was conducted in Luochuan Apple Experimental Station from2020 to 2022,and the method of reducing chemical fertilizer suitable for dryland apples on the Loess Plateau was summarized by studying the effects of different fertilization methods on soil microbial communities,and combining tree growth and results such as leaf SPAD value,nitrogen,phosphorus and potassium content,photosynthetic capacity,fruit yield,and quality.The results of the study showed that:1.Different fertilization methods can significantly change the composition of rhizosphere soil microbial species.The treatment without microbial agents(T1,T2,T5)had more varieties of rhizosphere soil microorganisms,more pathogenic fungi,and lack of beneficial bacteria.In the treatment(T3,T4)applied in combination with microbial agents,the rhizosphere soil bacteria formed a dominant flora dominated by Proteobacteria,and the abundance of bacteria with the functions of remediating soil pollution and degrading toxins was high,the number of soil pathogenic fungi decreased,and the related functions of soil microorganisms were enhanced.2.Organic fertilizers and microbial agents can increase the nutrient content and photosynthetic rate of leaves.Among them,the SPAD value,nutrient content and photosynthesis rate of leaves were significantly increased compared with the control in the treatment of compound fertilizer,farm manure and microbial agent(T4).3.Organic fertilizers and microbial agents can improve fruit quality.The external quality and internal quality of fruits were significantly improved compared with the control(T1,T2).The treatment of commercial organic fertilizer(T5)increased the intrinsic quality of the fruit significantly.Compared with the control,the external quality and internal quality of fruits in combination with microbial agents(T3,T4)were significantly improved,and the promotion effect between the treatments was the best. |
