What fertilizer should be applied to kiwifruit in spring? A detailed explanation of scientific fertilization methods
AbstractKiwifruit needs a topdressing of sprouting fertilizer in spring, generally applied in March, mainly a combined application of chemical fertilizer and organic fertilizer. The chemical fertilizer is mainly a formula fertilizer with high nitrogen, medium phosphorus and low potassium, and urea and diammonium phosphate can also be applied in combination in proportion. The organic fertilizer is mainly commercial organic fertilizer or biological organic fertilizer. Spring is the peak growth season for kiwifruit, which requires a large amount of nutrients. Fertilization can be carried out by the method of trenching and ring application, taking care not to damage the root system, and watering promptly after fertilization, which is more conducive to nutrient absorption and utilization.
I. What fertilizer should be applied to kiwifruit in spring
The topdressing of kiwifruit in spring can also be called sprouting fertilizer. Its main purpose is to promote sprouting and the growth of branches and leaves, thereby supplementing nutrients for the flowering period of kiwifruit and improving the fruit-setting rate. Fertilizing in March is optimal.
1. Fertilizer types and proportions
(1) Chemical fertilizer: The formula fertilizer is mainly a formula fertilizer with high nitrogen, medium phosphorus and low potassium, and urea and diammonium phosphate can also be applied in combination in proportion.
(2) Organic fertilizer: Mainly commercial organic fertilizer or biological organic fertilizer.
(3) Fertilizer proportion: According to soil nutrients and the fertilizer requirements of kiwifruit, the sprouting fertilizer can be mixed as follows: 100 jin of formula fertilizer and 160 jin of organic fertilizer mixed evenly, or 100 jin of urea, 20 jin of diammonium phosphate and 160 jin of organic fertilizer mixed evenly.
2. Fertilizer application amount
(1) Young trees: Each newly planted young tree can be applied with 0.2 jin of diammonium phosphate and 1 jin of organic fertilizer, or no sprouting fertilizer may be applied.
(2) Orchards beginning to bear fruit: For 5-7 year old trees, each tree can use about 2-3 jin of the fertilizer mixed according to the above proportion; for 4-year-old trees, each tree can be applied with about 1.5 jin.
(3) Full fruiting period: In 8-12 year old orchards, each tree can use about 3-4 jin of the fertilizer mixed according to the above proportion; for fruit trees over 13 years old, each tree can use about 4-5 jin.
3. Application method
Outside two-thirds of the distance from the tree canopy, that is, in a full-fruiting orchard 60-100 cm from the main trunk, hole application or radial trench application can be used, followed by covering with soil.
II. Points to note in kiwifruit cultivation
1. Prevent freezing damage in time
(1) The temperature in early spring is still relatively low, and kiwifruit has poor cold resistance. In many places, freezing damage is likely to occur in early spring. Therefore, in early spring, freezing damage prevention measures must be taken in time to avoid unnecessary losses.
(2) Generally, if the temperature in early spring is lower than 2°C, preventive work needs to be done. Freezing damage can be prevented by whitening the trunk or smoking.
2. Prune branches and leaves
(1) After kiwifruit is pruned in winter, supplementary pruning of branches and leaves is still needed in spring. This is because pruning diseased branches or dead branches in winter may not be thorough enough, so timely supplementary pruning is needed. In addition, excess branches and leaves also need to be pruned to prevent them from taking away nutrients.
(2) In order to better promote the growth of kiwifruit, it is necessary to promptly pinch the tips, remove buds and thin out flower buds of kiwifruit.
3. Tying branches and vines
(1) Tying the branches and vines of kiwifruit is a very important task. First select the main branches of the kiwifruit, then tie them along the trellis.
(2) During the tying process, other branches and vines need to be kept perpendicular to the main branches and vines, which helps promote the sprouting of winter buds.
(3) When the buds appear, all flower buds on the main vine need to be thinned out, and then a layer of branch-promoting agent should be applied on it, which helps promote the growth of side branches.
(4) Finally, thin out excess branches and leaves, then tie the fruiting branches to the trellis and let them crawl and grow, thereby reducing the incidence of disease.
4. Prevent and control pests and diseases
(1) In spring, work to prevent and control pests and diseases must be done in advance, such as preventing canker and root rot. Before the plant sprouts, a small amount of Baume degree lime sulfur mixture can be sprayed in the orchard and hymexazol can be used to drench the roots.
(2) The most direct method is to scrape off all the insect eggs and disease spots on the kiwifruit branches, and be sure to apply a layer of preventive pesticide, which helps the wound heal and avoids infection by other diseases.