Grape Fertilization Time and Methods
Scientifically mastering the timing of grape fertilization is key to improving fruit quality, and a reasonable combination of fertilization methods directly affects sugar accumulation and yield. There are significant differences in nutrient requirements at different growth stages, and growers need to develop precise fertilization plans based on phenological characteristics, making it easier to grasp the essentials of operation with the detailed illustration provided in this text.
Grape Fertilization Cycle Planning
Key Points for Fertilization Before Germination
When the temperature rises to 10°C, grape roots begin to activity. It is recommended to apply fast-acting nitrogen fertilizer (urea 20kg mu/acre) 7 days before the bud expansion, combined with deep furrow application (40cm from the trunk in a circular furrow) to promote the development of new shoots. Applying decomposed sheep manure (500kg mu/acre) at this time can improve soil structure.
Strengthening Nutrition Before Flowering
Foliar spray 15 days before budding, using a mixture of 0.2% boric acid and 0.3% potassium dihydrogen phosphate solution, focusing on the back of new leaves. Applying high-phosphorus water-soluble fertilizer (N-P₂O₅-K₂O=10-50-10) on the ground can promote inflorescence differentiation, and avoid fertilizing on rainy days to prevent loss.
Top-dressing During Key Growth Stages of Grapes
Management During the Young Fruit Expansion Stage
Apply balanced compound fertilizer (17-17-17) using the strip furrow method 7 days after flowering, combined with calcium magnesium fertilizer (5kg mu/acre) to prevent fruit cracking. It is recommended to apply in two doses: the first with nitrogen as the main nutrient to promote cell division, and 10 days later, add potassium fertilizer to accelerate sugar transport.
Plan for the Color Change and Maturation Stage
When the fruit firmness begins to decrease, apply potassium sulfate (15kg mu/acre) on the ground combined with foliar spraying of 0.5% amino acid calcium. At this time, nitrogen fertilizer should be strictly controlled, and humic acid should be applied to improve root absorption efficiency, maintaining 60% soil moisture during the color change stage is most beneficial for sugar accumulation.
Grape fertilization should follow the principle of 'promoting in the front and controlling in the back', focusing on nitrogen during the germination stage, supplementing boron during the flowering stage, balancing during the fruit expansion stage, and supplementing potassium during the color change stage. It is recommended to adjust the amount of fertilizer based on soil test data, and using a drip irrigation system can increase fertilizer utilization by over 30%, ultimately achieving dual improvements in quality and yield.