Detailed Explanation of Key Points of Autumn Fertilization Techniques in Apple Orchards
1. Fertilization principles: On the premise of increasing the application of organic fertilizer and building up soil fertility, emphasize potassium, increase nitrogen, stabilize phosphorus, and supplement micronutrients, and vigorously promote soil-testing-based formula fertilization.
2. Fertilization types: (1) Organic fertilizers mainly include: manure and urine, barnyard manure, compost, cake fertilizer, straw, miscellaneous fertilizer, and biogas fertilizer. (2) Chemical fertilizers mainly include: nitrogen fertilizer, phosphorus fertilizer, potassium fertilizer, compound (mixed) fertilizer, biological bacterial fertilizer, soil conditioner fertilizer, trace element fertilizer, and commercial organic fertilizer. It is strictly prohibited to apply untreated garbage, nitrate nitrogen fertilizer, potassium fertilizer containing chloride ions, undecomposed organic fertilizer, fertilizers explicitly prohibited by the state, and fertilizer products that have not been approved for registration.
3. Fertilization amount: Based on the nutrient content in the soil, that is, soil fertility, determine the target yield, and according to the fertilizer amount required for the target yield, the soil fertilizer supply capacity, the fertilizer content and utilization rate, determine the chemical fertilizer application amount on the basis of applying 3000—5000 kg of high-quality decomposed organic fertilizer per mu.
4. Fertilization period: Start after harvesting mid-season varieties and end in mid-to-late November.
5. Fertilization methods: (1) Ring ditch fertilization. Dig a ring-shaped ditch 20—40cm deep and 40cm wide at the outer edge of the vertical projection of the tree canopy for fertilization. (2) Radial ditch fertilization. With the tree body as the center, dig 4—6 radial ditches gradually deepening from the inside outward for fertilization. The ditch width is 30—50cm, the ditch depth is 20—40cm, and the ditch length exceeds the outer edge of the tree canopy. (3) Strip ditch fertilization. Dig strip ditches 20—40cm deep and 40—50cm wide at the outer edge of the vertical projection of the tree canopy for fertilization. (4) Whole-orchard broadcast application. After mixing the fertilizers evenly, spread them on the orchard surface, then turn them into the soil to a depth of 20—30cm. The above fertilization methods can be used alternately. During fertilization, the fertilizer and soil are required to be mixed evenly, and if irrigation conditions are available, irrigate promptly after fertilization.