Nutrient And Photosynthetic Characteristics Of Walnut Soils By Coupling Nitrogen Fertilizer With Mepazine And The Impact Of Yield Quality

Early-fruit walnut is the dominant tree species in southern Xinjiang,and it is also one of the main economic sources of local farmers.Due to the characteristics of quick effect,early results and high yield,the main-shaped walnuts tend to make the nutrient consumption of the tree too large.In addition,the regularity of the nutrient requirement of the fruit growers in the production is not clear,and it is easy to have insufficient nitrogen application or excessive nitrogen application.At the extreme,the tree's vegetative growth is too slow or too strong,resulting in a sharp decline in walnut yield and quality.Mepazine is a highly effective exogenous plant growth retardant that controls the elongation and enlargement of plant cells.Nitrogen fertilizer is combined with meperazine to achieve precise fertilization control technology with low input and high output.In this experiment,the main shape'Wen 185'walnut was selected as the test material,and four gradient coupling treatments of nitrogen fertilizer and mepazine were used to study the growth,photosynthetic,chlorophyll fluorescence,leaf anatomical structure,soil nutrient content,yield and The influence of quality,using the principal component method to comprehensively analyze and compare,the optimal nitrogen fertilizer application amount coupled with the optimum concentration of methotrexate spray,which provides an important theoretical reference for the scientific management,quality improvement and efficiency of walnut.The main findings are as follows:?1?The coupling of nitrogen fertilizer and meperazine has a certain regulation effect on the internode length and diameter of walnut.Appropriate nitrogen application rate and piperazine spray concentration can shorten the internode length and increase the diameter.Among them,when the nitrogen application rate was 1.425 kg·strain^-1 coupled with the sprayed concentration of 800 mg·L^-1?A2B3?,the results of ripening walnuts were shortened by 79.03%and the diameter increased by 20.34%.?2?Comprehensive comparison of nitrogen fertilizer and meperazine in the treatment,the application of nitrogen concentration of 1.425 kg·strain^-1 coupled with meperazine sprayed at a concentration of 800mg·L^-1?A2B3?,and the expansion period of 20-40 cm The nitrogen content of 40cm soil layer was 8.90%lower than that of the control,indicating that the utilization rate of soil nitrogen fertilizer was higher in this period.The nitrogen application rate was 1.425 kg·strain^-1 coupled with the sprayed concentration of 800mg·L^-1?A2B3?.The maximum phosphorus content in the depth of 20-40 cm in the expansion period was13.58 mg·kg^-1.Under the treatment of 1.25 kg·strain^-1 coupled with meperidine,the concentration of potassium in the soil of 20-40 cm was 20.92%lower than that of the control.?3?The combination of nitrogen fertilizer and mepazine had different effects on photosynthetic index and chlorophyll fluorescence parameters of walnut leaves.The net photosynthetic rate?Pn?during the expansion period was 0.475 kg·strain^-1,and the coupling concentration of meperidine was 1 000 mg·L^-1?A1B4?.The highest value was 26.95 mol·m^-2·s^-1..The transpiration rate?Tr?was 5.49%higher than that of the control when the nitrogen application rate was 0.475 kg·strain^-1 and the concentration of meperidine was 800 mg·L^-1?A1B3?.In the hard core stage,the nitrogen application rate was 3.158 kg·strain^-1,and the coupling concentration of meperazine was 1 000 mg·L^-1?A4B4?,and the initial fluorescence?Fo?was the highest value of 151.00.?4?The coupling of nitrogen fertilizer and mepazine had a great influence on the mixed bud density of walnut branches,and the nitrogen application rate was 1.425 kg·strain^-1 coupled with the concentration of piperazine sprayed at 600 mg·L^-1?A2B2?.The mixed bud density was present at a maximum of 68.97buds·m^-1.The number of walnut fruit per plant was improved in each coupling treatment,and the highest value was 138.5 under the treatment of 600 mg·L^-1?A1B2?when the nitrogen application rate was 0.475kg·strain^-1.?5?There was a significant difference in the appearance index of walnut between the nitrogen fertilizer and the piperazine.The seeding rate and the reducing sugar content of the walnut fruit were 1.425kg·strain^-1 coupled with the piperazine.Under treatment with 600 mg·L^-1?A2B2?,it was 63.45%and 4.09%higher than the control.The yield per plant,nut weight and fat content of walnut fruit were increased by65.28%compared with the control when the nitrogen application rate was 1.425 kg·strain^-1 coupled with the sprayed concentration of 800 mg·L^-1?A2B3?,18.93%,24.00%.In summary,the combination of nitrogen fertilizer and methotrexate has a certain regulation effect on the growth and development of walnut.Principal component analysis comprehensive ranking results showed that the effects of each coupling treatment on the growth and development of walnut were as follows:the application rate of 1.425 kg·strain^-1 and the piperazine spray was 800 mg·L^-1?A2B3?,followed by Shi The nitrogen concentration of 1.425 kg·strain^-1 and the piperazine sprayed at a concentration of 600 mg·L^-1?A2B2?,and the third place was a nitrogen application rate of 1.425 kg·strain^-1 and the piperazine spray concentration of 1 000 mg.·L^-1?A2B4?.