Four Fertilization Methods for Pollution-Free Cherry Cultivation

1. Radial trench or ring trench method: For the radial trench method, dig outward starting 50 cm from the trunk, narrow and shallow on the inside (30 cm) and wide and deep on the outside (40-50 cm), with the trench extending to 20 cm beyond the canopy projection, and dig 4-6 trenches per tree. For the ring trench, dig at the canopy projection, with a width of 50 cm and a depth of 40-50 cm. Both methods involve evenly scattering the fertilizer in and mixing it thoroughly with the soil to avoid burning the roots. After application, cover with soil and water, or apply after rain when soil moisture is good.

2. Broadcast application over the whole orchard: This method is suitable when the root system has spread throughout the entire orchard. Evenly scatter the fertilizer over the orchard and turn it into the soil. Because this method applies fertilizer shallowly (about 20 cm), it easily causes the roots to rise toward the surface and reduces the root system's resistance to adverse conditions. It is best to alternate it with the radial trench method or the ring trench method.

3. Hole storage of fertilizer and water: Dig holes 35 cm deep and 30 cm in diameter along the outer edge of the canopy, place a grass bundle 20 cm in diameter and 30 cm high into each hole, 5 cm below the ground surface, then pour in 4 kg of nutrient solution. The number of holes depends on the size of the canopy; generally dig 4-6 holes per tree, then cover with plastic film, poke a small hole in the film at the center of the hole, and apply fertilizer (dissolved in water) and water through the small hole. Usually seal with a stone to prevent evaporation. Since the hole is 5 cm below ground level, rainwater can circulate into the hole during open-air rainfall; if there is no rain, water with 4-5 kg of water about every 20 days, and stop watering once the rainy season begins. Compared with ordinary soil topdressing methods, it can use half the fertilizer, is economical and effective, and has a large yield-increasing effect. It should be vigorously promoted especially in protected cultivation.

4. Foliar topdressing: Foliar topdressing during the growing season is an effective supplementary fertilization method. It has the advantages of saving labor, being absorbed quickly, being evenly distributed, and having a high utilization rate. (1) The suitable concentrations for foliar spraying on cherries are: urea at 0.3%. Ammonium phosphate and potassium phosphate are both used at 0.5%-1%. Potassium chloride and potassium nitrate are both used at 1%. (2) Spraying stage and application time: It can be used from the beginning of leaf expansion until the leaves stop growing, allowing timely supplementation of nutrients during the key periods when cherries need fertilizer. In summer, it is suitable to apply before 10:00 and after 16:00 to avoid too-rapid evaporation causing phytotoxicity. (3) Spraying frequency: Generally spray once every 15-20 days, and it can be done together with pesticide spraying by putting the fertilizer into the pesticide and spraying them together. (4) How to use: The fertilizer can be directly added to water at the required concentration, and once dissolved it can be sprayed. When spraying, focus on spraying the underside of the leaves, because the underside of the leaves has less cuticle and is easier to absorb.