Evaluation Of Soil And Tree Nutritional Status And Research On The Effect Of Formulated Fertilization In ’Cuiguan’ Pear Orchards Of Shanghai

The ’Cuiguan’ pear,the major pear cultivar in Shanghai and the middle and lower reaches of the Yangtze River,is favored among fruit farmers in production.And orchard’s nutrition is important for the healthy growth,yield formation and quality improvement of fruit trees.Therefore,knowing the tree nutrition and soil nutrition in the orchard,and developing accurate diagnostic fertilization technology,will promote the scientific and rational fertilization of the ’Cuiguan’ pear orchard in Shanghai,which is of great significance for improving fruit quality,yield and economic benefits.In this experiment,the soil nutrition,leaf nutrition,fruit quality and yield of 36’Cuiguan’ pear orchards in Shanghai were investigated and analyzed to establish the standard for leaf nutrients of high-quality and high-yield ’Cuiguan’ pear in Shanghai.Furthermore,nutritional diagnosis and the effect of formula fertilization was researched.The main results are as follows:1.The soil pH value of the ’Cuiguan’ pear orchards in Shanghai has a large variation.The acidic soil occupied 31%.The soil EC value is generally moderate;the soil organic matter content was rich;the total nutrient content were relatively suitable,but some effective nutrients content were deficient.2.Established the standard range of the contents of 10 nutrient elements of the high-quality and high-yielding ’Cuiguan’ pear in Shanghai:N(2.02～2.45%),P(0.11～0.15%),K(1.32～1.68%),Ca(2.31～3.04%),Mg(0.34～0.42%),Fe(64.52～87.37 mg/kg),Mn(64.62～183.01 mg/kg),Cu(74.78～124.24 mg/kg),B(21.51～35.83 mg/kg),Zn(19.92～39.11 mg/kg).3.The contents of N,P,and K in the leaves of the ’Cuiguan’ pear orchards in Shanghai are 1.19～2.87%,0.08～0.20%,0.87～2.47%.The leaf P element was relatively suitable,pear orchards with insufficient N element were 35%,excessive and lack of K elements coexist;31%of pear orchards have insufficient Ca and Mg content;Fe and Cu elements are generally higher;the Mn,B and Zn contents in leaves were mainly in suitable levels.4.Fertilization experiments show that compared with conventional fertilization,formula fertilization significantly increased the single fruit weight,soluble solid content,soluble sugar content,and sugar-acid ratio of ’Cuiguan’ pears;it also has a good promoting effect on the increase of fruit aroma substance content;the fruit yield of the pear tree compound microbial fertilizer(formula fertilizer)treatment is slightly lower than that of the Jinzi brand ternary compound fertilizer treatment;in terms of the impact on the nutrient level of the tree,the pear tree compound microbial fertilizer treatment can significantly increase the nutrient contents of the tree,such as Ca,Mg,Fe,B.5.Through different fertilization treatments,it was found that with the increase in the amount of pear tree compound microbial fertilizer(formula fertilizer),the fruit weight of the ’Cuiguan’ pear increased,the hardness decreased,the soluble solid content and soluble sugar content increased,the titratable acid content decreased,and the fruit aroma substance content increased.In terms of the effect on fruit yield and tree nutrient level,the same effect of applying 3 kg of pear tree compound microbial fertilizer to increase yield and tree nutrient level is the best.