Effects Of Bio-organic Fertilizer On Soil Quality And Apricot Fruit In Apricot Orchards

In recent years,due to unreasonable fertilization by fruit farmers,it not only has the imbalance of soil nutrients in apricot orchards been caused,but also reduces the quality of the apricot(Armeniaca vulgaris Lam.),reducing the profits of fruit farmers.Therefore,applying bio organic fertilizer to apricot orchards to determine the optimal application amount of bio organic fertilizer provides theoretical basis and technical guidance for scientific fertilization in local apricot orchards.This study was conducted in the apricot orchard of Xixianzi Village,Yuxian County,Zhangjiakou City,Hebei Province from 2021 to 2022,using 15-year-old ’mugua’ apricot and’youyi’ apricot trees in the local apricot orchard were used as experimental materials to investigate the effects of different application rates of bio-organic fertilizer(0 kg/plant,1 kg/plant,2 kg/plant,3 kg/plant,with 0 kg/plant as the control check)on the soil physicochemical properties,soil enzyme activity,soil microorganisms,apricot fruit quality,and yield of the apricot orchard.The main test results are as follows:(1)Applying bio-organic fertilizer to the soil of the apricot orchard for two consecutive years increased the soil nutrient content to varying degrees,while improving the soil pH value.In different soil layers,the interannual variation of soil organic matter content in the three bio-organic fertilizer treatment groups showed a trend of 2022>2021,with the 2 kg/plant treatment group showing the most significant change.The content of available nutrients in the soil also increased to varying degrees,with the best effect on improving the alkaline nitrogen content.The 2 kg/plant treatment group ’mugua’ apricot and ’youyi’ apricot increased by 58.9%,80.8%,212.9%,and 141.0%,153.4%,and 141.3%,respectively,in the 0-20 cm,20-40 cm,and 40-60 cm soil layers compared to the previous year.The effective phosphorus content in the soil was significantly higher in the three bio-organic fertilizer treatment groups of ’mugua’ apricot than in control check(CK),with the most significant change being in the 2 kg/plant treatment group.In 2021,different soil layers increased by 111.0%,149.0%,and 141.2%compared to CK,respectively.In the 20-40 cm and 40-60 cm soil layers of the three bio-organic fertilizer treatment groups,the soil available potassium content in the second year was significantly higher than that in the first year.(2)The application of bio-organic fertilizers increased soil enzyme activity.During the same period,the soil sucrase and phosphatase activities of the three groups treated with bio-organic fertilizers showed an increasing trend compared to CK,and also showed an increasing trend year by year with the increase of fertilization years.With the increase of fertilization years,the soil catalase activity of the three bio-organic fertilizer treatment groups ’youyi’ apricot was significantly higher than that of CK.In 2022,’youyi’ apricot increased by 72.0%,61.3%,and 51.6%compared to CK in the 0-20 cm soil layer,respectively.Moreover,except for the surface soil of’mugua’ apricot in the first year,the soil catalase activity in the second year was significantly higher than that in the first year.(3)The application of bio-organic fertilizer improved the quality of apricot fruit and increased yield.From 2021 to 2022,the content of soluble solids and total polyphenols of ’mugua’ apricot under the treatment group of 3 kg/plant bio-organic fertilizer was the highest,the yield,solid acid ratio and soluble sugar content of’mugua’ apricot under the treatment group of 2 kg/plant bio-organic fertilizer were the highest,and the content of titratable acid was the lowest.The yield of the three bio-organic fertilizer treatment groups in the second year was significantly higher than that of the previous year,with an increase of 36.6%,34.3%and 24.2%respectively.From 2021 to 2022,the highest yield of ’youyi’ apricot was observed in the 2 kg/plant bio-organic fertilizer treatment group,with 13.07 kg/plant and 11.16 kg/plant,respectively.The kernel yield,fat,soluble sugar,and starch content of the 2 kg/plant bio-organic fertilizer treatment group in 2022 were the highest,increased by 14.4%,4.7%,20.4%,and 11.0%compared to CK,respectively.(4)After the application of bio-organic fertilizer,the alpha diversity and evenness of surface soil fungi in the ’youyi’ apricot treated group with 2 kg/plant bio-organic fertilizer were significantly increased,including Shannon index,Simpson index,and Pielou index of soil fungi.The e-index increased by 11.2%.2.5%,and 7.8%respectively compared to CK;Different fertilization rates of bio-organic fertilizers have changed the community structure of soil fungi and bacteria,and soil microorganisms have a correlation with soil physicochemical factors and soil enzyme activity.The application of bio-organic fertilizers also increased the abundance of beneficial bacteria such as Streptomyces,Nocardioides,and beneficial fungi such as Metarhizium,Penicillium,and Trichoderma.Comprehensively compare the effects of four different fertilization treatments’mugua’ apricot and ’youyi’ apricot in apricot orchard on the measured indicators,the results show that the treatment of 2 kg/plant bio-organic fertilizer can achieve better production requirements,and achieve the purpose of reducing fertilizer application and improving soil quality.Therefore,2 kg/plant of bio-organic fertilizer can be the recommended fertilization program for high yield and quality of apricot orchards in Yuxian County,Zhangjiakou.