| The area and yield of peach have been ranked as the fourthin recent years. Its industry has gradually entered the specialized, intensive, large-scale development track. However,since the fertilizer and water ofmost peach orchards under mismanagement,it leads the unit area yield and quality at a disadvantage in international competition. Confronted withthe improper fertilization,low fertilizer utilization and other production problems in peach orchards and in order to achieve the high yield and quality purpose, thisresearch is divided into two parts.One,the experiment is conducted to investigate the effects of topdressing different levels potassium fertilizer on tree nutrition and fruit yield and quality of the middle-late mature cultivar‘Chongyanghong’peach before harvest. Second, the study analyzed the influence of different fertilization treatments on soilenvironment,tree nutrition,fruit quality and yield through the fertilization with injectiontechnology.The main conclusions are as follows:1.The yield is increased by 10.58%~23.58% after topdressing potassiumin in fruit growth period which compared with K0 and it is the highest when the potassium fertilizer rate is K2(0.70kg/tree). The yield increasing effect accords with the law of "diminishing returns".2. Compared to K0, topdressing potassium could improve the intrinsic quality in different degrees, especially the treatment of K2 can significantly increase the contents of soluble solid、soluble starch、N and K.Topdressing potassium could promote the accumulation of the tree nutrition at the late stage of fruit development and K2 treatment of Pn,Tr,Gs and the mass fraction of N,soluble starch,soluble sugar and reducing sugar of the leaf are significantly or extremely significantly higher than K0. As well,the contents of N and K of the branch respectively is1.43 and 1.50 times higher than K0. There was no significant difference between other treatments.3. With the same amount of fertilizer, the contents of the total N,P and K are not significant in 0-20 cm and 20-40 cm soil layer during the fast growth stage of young fruit, but the content of available nutrient in the soil of injection fertilizing was significantly lower than that in the soil of radial ditch fertilizing.Apart from a few treatments, the majority the contentsof the total N,K and available N,K of the total amount of fertilizer treatments were significantly higher than half the amount of fertilizer. For total P and available P contents in0-20 cm soil layer, the whole amount of fertilizer slightly more than half the amount of fertilizer.It doesn’t reach the 5% significanc eleve between the NPK(R), 1/2 NPK(R),NPK(I)and 1/2 NPK(I) four treatments. These results indicated it is more advantageous to the root to absorb and use fertilizers.The soil contents of available Nand K under the treatment of NPK(I) of 0-20 cm and 20-40 cm soil are the highest in the final stage of the growth season,significantly higher than the radial ditch fertilizing and increased by 16.61and12.56% as well as 10.15% and 23.93%, respectively.No significant differences appeared compared to 40-60 cm soil.The contents of total N and K under the treatment of NPK(I) significantly lower than NPK(R) treatment.With the same amount of fertilizer, the contents of the total P and available P are not significant in 0-20 cm between injection fertilizing and radial ditch fertilizing.Compared with the fast growth stage of young fruit,the differences of total P and available P contents are weak. These results indicated that injection fertilizing can improve the solubility of difficult soluble inorganic fertilizer and improve soil available mineral nutrients,but it has little effect on the P.The soil organic matter content of 0-40 cm soil of the fertilization with injection were significantly lower than the radial ditch fertilizing in the final stage of the growth season. It shows that injection fertilization can accelerate the decomposition of soil organic matter mineralization.Besides, the activity of soil invertase,catalase and urease of 0-60 cm soil under the treatments of injection fertilizing were significantly higher than the radial ditch fertilizing and this rule for alkaline phosphatase was applicable to 0-20 cm soil. The change law of soil microbial quantity was basically identical with soil enzyme activity.4.The N, K, Zn contents of leaves was the highest in the treatment of 1/2 NPK(I), and significantly higher than other treatments. The differences are not obvious of P contents.Ca contents of injection fertilization are significantly higher radiation ditch fertilization. Mg, Fe,Mn contentsof NPK(I) are the highest.On the other hand, injection fertilization can accelerate chlorophyll synthesis of shoots leaves and enhance their sugar contents.5.Single fruit weight and soluble solids contents of NPK(I) are significantly higher than other treatments, and, respectively, compared with the NPK(R) treatment increased by12.24% and 11.21%.The highest yield is the 1/2 NPK(I) treatment which reaches 65.25 kg,but it doesn’t reach the 5% significanc eleve with NPK(I). |
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