The Effects Of Different Content Components Of Localized Fertilizers On Apple Growth And Fruit Quality

The essentiality of calcium in fruit trees’growth and development is undeniable,and its role in determining fruit quality is paramount.However,physiological disorders in fruit trees resulting from calcium deficiency have led to physiological diseases in apples and a decline in fruit quality.To address this issue,a research team has invented a positioning fertilization machine that has been shown to improve soil quality,increase fertilizer utilization and efficiency,as well as prolong fertilizer efficacy.This study aims to explore the impact of different components of the positioning fertilization machine on soil improvement and calcium absorption by trees.The experiment was divided into two stages.In the first stage,pot experiments were conducted to identify content components that have a significant effect on soil improvement and calcium absorption in trees.In the second stage,field experiments using’Venus Gold’and’Fuji’apples were carried out to evaluate the impact of different components on calcium absorption in soil,trees,and fruits.The study aims to provide a theoretical foundation for promoting efficient and rational fertilization of apples and the positioning fertilization machine.The results of the study indicate that:1.In the potted plant experiment,the addition of growth-promoting agents significantly increased various indicators of root system,such as total root length and root tip number,and improved root vitality.Among them,the DA-7 treatment had the most significant effect,with an increase of 78.9%.In the field experiment,all treatments increased the relative content of chlorophyll in leaves.Potassium humate had the most significant effect on chlorophyll,with a growth rate of 19.3%in August compared to July.The photosynthesis indicators of’Fuji’and’Venus Golden’apple leaves in July,August,and September showed an overall trend of first increasing and then decreasing.Noteworthy disparity in the aggregate calcium content between‘Fuji’and‘Venus Golden’was observed,and the amount was essentially the same between the two varieties.The VB6 treatment in September had the most significant difference in total calcium content in both’Fuji’and’Venus Golden’.2.Different contents of the components in the positioning fertilizer had the most significant impact on soil urease activity.In the field experiment,compared with the control,the soil urease activity in’Fuji’was significantly higher in VB6 in August,with an increase of5.8%,while in’Venus Golden’,urease activity was significantly higher in potassium humate in August,with an increase of 5.7%.The impact of each treatment on the number of soil microorganisms was significantly different.Compared with July and August,the number of bacteria in the VB6 treatment in September increased significantly.In September,the number of bacteria was 34.8%higher than that of CK in the same month and increased by 49.1%compared to August.There was no significant difference in the nitrogen,phosphorus,and potassium elements in the soil mineral element content between the two varieties,while the total calcium content in the soil showed an increasing trend in July,August,and September.In addition to the trend,after the comprehensive analysis of leaf and soil mineral elements,the DA-7 and VB6 treatments showed significant differences in the various mineral element content.3.Compared with the control,VB6 treatment significantly improved fruit quality,increased total phosphorus and calcium content,and decreased fruit N/Ca and Mg/Ca ratios.VB6 and DA-7 treatments significantly altered the composition of different forms of calcium in fruits,increased the content of pectin calcium in different parts,and significantly increased the content of original pectin（PP）,water-soluble pectin（WSP）,and cellulose（CLL）compared to other treatments.They also decreased the activity of cellulase（Cx）,pectin methyl esterase（PME）,and polygalacturonic acid enzyme（PG）,with VB6 treatment being the most significant.Laser confocal microscopy observation revealed that VB6 and DA-7 treatments resulted in compactly arranged cells with the strongest Ca²⁺signals.In summary,this experiment analyzed the effects of different components of the location fertilization apparatus on calcium absorption in fruit trees’rhizosphere soil,tree body,and fruit.The results showed that VB6 and DA-7 components had a good effect in effectively increasing the calcium content in fruit trees and improving fruit quality,which is an excellent recipe for efficiently supplementing calcium in apples.