What fertilizer can be applied to walnut trees and how to grow walnuts?

After germination in spring, the phenological process of main organs of walnut is extremely fast. The main characteristics of this period are strong respiration, fast growth and vigorous physiological activities, especially a large number of fruitful plants need more nutrients, so it is necessary to apply available nitrogen and phosphorus fertilizers before germination in spring. Fertilization should account for 50% of the annual topdressing. After May and June, the fruit developed rapidly and the flower buds began to differentiate. The size of fruit development and the quality and quantity of flower bud differentiation depend on the balance of nutrient consumption and accumulation. Therefore, special attention should be paid to topdressing nitrogen fertilizer and irrigation in June. At this time, the amount of topdressing is 30% of the amount of topdressing in the following year. After entering July, the fruit has hardened and the nucleoli has begun to develop. At this time, quick-acting phosphate fertilizer should be used as topdressing, supplemented by a small amount of nitrogen and potassium fertilizer. Its topdressing amount is 20% of the annual topdressing amount. The following is the fertilization scheme of walnut for your reference: 1. Base fertilizer: apply base fertilizer in autumn, and the earlier the fertilization, the better. It is too late to supplement the nutrients needed by the tree in time, which affects the quality of flower bud differentiation. Generally, it is the best time to smear before and after harvesting. 1-3 years, young tree stage: 3 kg of organic fertilizer and 0.25 kg of compound fertilizer (three 15, meaning the content of nitrogen, phosphorus and potassium). 4-6 years, young tree stage: 4 kg of organic fertilizer and 0.5 kg of compound fertilizer (3 15). 7- 10 year, the first fruit: 5 kg of organic fertilizer and 0.5 kg of compound fertilizer (3 15). 11-15, the first fruit: 8 kg of organic fertilizer and 0.5 kg of compound fertilizer (315). 16-20 years, full fruit period: organic fertilizer 10 kg, compound fertilizer 1 kg (3 15). Methods such as ring fertilization (young tree stage), radial fertilization or furrow fertilization (fruiting stage) can be adopted, and furrow application 15-20 cm deep application combined with deep ploughing in autumn is best to improve soil application. Second, topdressing: The frequency and time of topdressing are related to climate, soil, tree age, tree potential and other factors. There are more growing points of new shoots in germination stage, followed by flower organs; At flowering stage, the nutrients in the tree first meet the needs of flower organs; In the fruit-bearing period, the nutrients of the tree first meet the needs of the fruit, and then are the growing points of the new shoots. Throughout the year, the flowering and fruit-setting period is the key period for fertilization. Young walnut trees are topdressing 2-3 times a year, and adult walnut trees are topdressing 3-4 times. 1. First topdressing: Early-fruiting walnuts are usually topdressing before female flowers bloom, and late-fruiting walnuts are topdressing at the early stage of leaf development. The fertilizer is mainly available nitrogen fertilizer, and 200 g-500 g urea is about 20 cm shallower than the base fertilizer. 2. Top dressing for the second time: After the early-fruiting walnut blooms, the late-fruiting walnut is topdressing at the end of leaf development. Fertilizer: urea 300g, calcium superphosphate 500g, potassium sulfate 100g, the method is the same as the first time. 3. Top dressing for the third time: After the walnut is hardened, topdressing urea100g, calcium superphosphate 500g and potassium sulfate 200g at the fruiting stage. The method is the same as the first time. 4. The fourth topdressing: after the fruit is harvested, the organic fertilizer is 5- 10 kg, urea is 200g, calcium magnesium phosphorus is 500g, and potassium sulfate is 200 g.. 3. Spraying borax on the leaves at flowering stage can improve the fruit setting rate, spraying ferrous sulfate in May-June can thicken the leaves of trees and increase photosynthesis, and spraying potassium sulfate in July-August can effectively improve the quality of nucleolus and increase yield.