Study On The Integrated Fertilization Technology Of Water And Fertilizer In Qiaohua ’Ruixue’ Apple Orchard In Longdong Area Of Gansu Province

The fertilization period,nutrient distribution ratio,irrigation period and application amount in the fertilizer and water management of the apple orchard affect the yield and fruit quality.Therefore,in this study,the orchard in Longdong area of Gansu Province was selected,and the fruit tree‘Ruixue’apple in the full fruit period was used as the test material.The fertilizer nutrient distribution ratio test at different topdressing periods and the stage topdressing combined with irrigation test were used to study the effects of different topdressing periods and stage topdressing combined with irrigation on the quality,yield and mineral nutrient content of apple fruit under the labor-saving water and fertilizer integration mode.The optimal fertilization period,nutrient distribution ratio and fertilizer-water coupling ratio of apple in Longdong area of Gansu Province under the labor-saving water and fertilizer integration mode were determined,which provided a scientific reference for further realizing the light and simplified fertilizer and water management of the tree orchard and the high quality and high yield of apple.The following results were obtained:1.Fertilizer nutrient distribution ratio test at different topdressing periods.The results showed that the nutrient ratio of N:P₂O₅:K₂O in each period was 1.5:0.8:1 in germination stage and 1:1.2:1.5 in expansion stage（CK）.Compared with the germination stage 1:0.25:0.25,flowering stage 1:1:0.5,young fruit development stage 0.5:1:0.25,fruit expansion stage 0.5:0.5:1,secondary expansion stage 0.5:0:1,fruit maturity stage 0:0:1.5（T3）,the fruit yield was the highest,which increased by 16.48%,and the fruit commodity rate also increased,reaching 80.24%.The partial factor productivity of fertilizer increased by 9.64%～16.51%compared with the conventional two times topdressing.Compared with the nutrient distribution ratio treatment（CK）at the two topdressing stages,the nutrient distribution ratio treatment（T）at the six topdressing stages increased the fruit hardness,vitamin C content,soluble sugar content and relative total volatile substances,but the fruit color decreased.The content of mineral elements in fruit,leaf and soil changed differently after harvest,and there were significant differences among treatments.2.The principal component analysis was used to comprehensively analyze the 14 main quality indexes of the fruit,and the effects of different nutrient distribution ratios on the comprehensive quality of apples were analyzed.The results showed that the comprehensive score of fruit quality was better in the six topdressing periods,and the comprehensive score of fruit quality was the lowest in the two topdressing periods.The comprehensive quality score of fruit was the highest in the germination period 1:0.25:0.25,flowering period 1:1:0.5,young fruit development period 0.5:1:0.25,fruit expansion period 0.5:0.5:1,secondary expansion period 0.5:0:1,fruit maturity period 0:0:1.5（T3）.3.Stage topdressing combined with irrigation test.The results showed that the single fruit weight,fruit quality,yield,commodity rate and partial factor productivity of fertilizer were the highest in the treatment of increasing topdressing period combined with irrigation,6 times of root domain injection topdressing+6 times of irrigation（P3）.The highest single fruit weight was 321.33 g,and the average yield per plant was 78.8 kg.The relative total amount of volatile substances in pulp and peel was the highest,and the hardness of peel and pulp was the highest.The contents of soluble solids,vitamin C and other indicators increased,and the color of peel decreased.Staged fertilization combined with irrigation had no significant effect on the growth potential of fruit trees.Staged topdressing combined with irrigation had a significant effect on the content of mineral elements in fruits,leaves and soil during different topdressing irrigation periods,but there was no significant difference in the content of mineral elements between fruits and leaves,and there was a significant difference in the content of mineral elements in soil.4.Through the economic benefit analysis of different stages of topdressing combined with irrigation treatment,through the economic benefit analysis,increase the topdressing period,root injection topdressing 6 times fertilization labor cost is the lowest,save time and labor;increasing irrigation,root domain injection can take into account both fertilization and irrigation,greatly improving work efficiency,saving time cost and manpower,while improving fertilizer utilization and reducing fertilizer accumulation in the soil.5.The comprehensive results showed that the recommended fertilization scheme for Qiaohua‘Ruixue’apple orchard in Longdong area of Gansu Province was as follows:the fertilization amount was 4.98 kg/plant,the fertilization period and nutrient distribution ratio were 1:0.25:0.25 at germination stage,1:1:0.5 at flowering stage,0.5:1:0.25 at young fruit development stage,0.5:0:1 at first fruit expansion stage,0.5:0:1 at second fruit expansion stage and 0:0:1.5 at mature stage;the irrigation period was germination stage,flowering stage,young fruit development stage,fruit expansion stage（2 times）and maturity stage,and the irrigation amount was 50 L/plant.