Fertilizers commonly used for loquat cultivation include human urine, animal manure, cake fertilizer, compost, garbage fertilizer, fire soil and chemical fertilizer. According to the mineral nutrient requirements of loquat growth and development, loquat is a high potassium-demanding plant. The potassium content of loquat fruit is almost three times more than that of nitrogen. Excessive nitrogen fertilization results in large fruits. However, the color and flavor are not strong and the appearance and quality are poor. If there is too much potassium fertilizer, the fruit will have increased sugar content, but coarse and hard flesh. Therefore, various fertilizer elements need to be properly matched.
A、Fertilization of young loquat trees
For young loquat trees, fertilizer should be applied 5~6 times throughout the year. And use the method of thin fertilization and diligent application, about once every two months. Each plant should be fertilized with 15~25 kg of well-rotted dilute human manure and urine or 0.15~0.25 kg of compound fertilizer. At present, the compound fertilizer more commonly used in the market is produced by Nagric.
B、Fertilization of adult loquat trees
For adult loquat fruiting trees, fertilization is generally applied three times a year. The arrangement is mainly based on the fertilization characteristics of loquat and its weathering period. The amount of fertilizer applied varies slightly from place to place according to the actual situation.
This fertilization is usually done in May to June. The main purpose is to replenish the nutrients consumed by fruiting, restore the tree’s strength, and promote the robustness of summer tips. As well as promote root growth and flower bud differentiation well. Fast-acting fertilizer is the main purpose. At the same time, combined with deep turning, apply a large amount of well-rotted organic fertilizer. The ratio of nitrogen, phosphorus and potassium fertilizer is generally 3:2:2. The amount of fertilizer applied accounts for about 40% to 50% of the annual fertilizer application. Late ripening varieties can be applied earlier than before fruit picking. For example, if each plant produces 35 kg of loquat fruit, each loquat tree should be fertilized with 1~3 kg of 45% orchard compound fertilizer and 2~5 kg of oil blight.
This fertilization is generally carried out in September~October. It is applied in the fall when flower bud differentiation is basically finished and flower spikes start to appear. This can provide the nutrients needed for flowering and fruiting and the development of nutritious autumn tips. It will promote good flowering and improve the plant’s resistance to cold. Organic fertilizer is the mainstay. The ratio of nitrogen, phosphorus and potassium fertilizer is usually 5:4:5, and the amount of fertilizer applied is about 30% to 40% of the annual fertilizer amount. Apply 1~2 kg of oil blight and 0.5~1.5 kg of 45% orchard compound fertilizer per plant.
3、Spring tip strong fruit fertilizer
This fertilization is generally carried out in February to March after fruit thinning. The role of this fertilization is to promote the growth of spring tips and root system, supplying the nutrients needed for the growth of young fruit. This will promote the growth of young fruits, reduce fruit drop, and promote and enrich the spring tips. We generally use fast-acting fertilizers with compound fertilizers to apply. The ratio of nitrogen, phosphorus and potassium fertilizer is generally 3:4:3.
If there is more phosphorus fertilizer in the soil, or the amount of fruit hanging at that time is low, the proportion of phosphorus fertilizer can be reduced. If the tree is not vigorous, increase the proportion of nitrogen fertilizer. The amount of fertilizer applied is about 20% of the annual fertilizer application. February is the period of maximum root growth throughout the year, so the depth of fertilization should be shallow to avoid root injury.
After fruit picking, apply 30~35 kg of chicken manure and pig manure per plant in combination with tillage and cultivation. When loquat trees bear a lot of fruits, cultivate the soil during the period of rapid fruit expansion. Apply 30~35 kg of chicken manure and pig manure per plant. When loquat trees bear a lot of fruits, spray 2~3 times of foliar fertilizer solution before the rapid fruit expansion period, once at 10 days interval.
C、Fertilization method of loquat
The fertilization effect of loquat is closely related to the fertilization method. The absorption root system of loquat trees mainly concentrates in the soil layer at the periphery of the crown projection, and the fertilization site is at the drip line of the loquat crown in production. We can also take advantage of the fertilizer-oriented nature of the loquat root system and apply fertilizer at a place slightly separated from the root concentration. Guide the root system to expand deeper or outward to expand the root range.
In addition, we need to consider the characteristics of the fertilizer. For example, phosphorus fertilizer is poorly mobile and easily fixed by red soil. Therefore, we need to apply phosphorus fertilizer deeply and in holes, between the roots of loquat trees. This will improve the absorption rate of phosphorus fertilizer. After applying calcium superphosphate or bone meal, we can mix it with compost such as ring manure, stable manure or human manure and urine. Then, we wait until decomposition before applying it for better results.
Ring fertilization also known as rotational fertilization. We dig a ring trench slightly outside the periphery of the loquat canopy. Then we apply the fertilizer and finally cover the soil. The base fertilizer trench should be deeper, generally 40~50 cm. The follow-up trench should be shallow, generally 15-30 cm. The fertilizer application trench requires outward movement from year to year. This fertilization method has the advantages of easy operation and economic use of fertilizer. However, easy to cut off some fast-growing horizontal roots, and fertilization range is small, which should be noted in the selection.
Take the main stem as the center, rake the soil into a disc. The place shallow against the main stem, the further away from the main stem, the deeper. We also make only flat-bottom shaped fertilizer trays. We take the mound of soil raked out and place it around the outside of the tray to form the edge of the soil ridge. After applying fertilizer, then mulch the soil. This method is shallow, the water is easy to hurt the roots, it is appropriate to use for chasing fertilizer. However, the long-term use of this method of fertilization will cause the root system of loquat trees to move up.
3、Radiation ditch fertilization
With the trunk of loquat tree as the center, dig 6~8 radial trenches at 60~80 cm from the trunk, 20~30 cm deep, and apply fertilizer in the trenches. Change the position of the trenches every other year or every other time to increase the absorption surface of the root system of loquat trees. This method has less root injury and is more effective if combined with ring fertilization. But when digging ditches, avoid large roots to avoid damaging them.
4、Strip ditch fertilization
Open strip ditches on both sides of the drip line of loquat crown, or open strip ditches between rows or plants in loquat garden. Fertilizer ditch should be shallow, 15-30 cm. Then apply fertilizer in the trench and cover the soil. The next time you apply fertilizer, you can change the other two sides and move outward year by year, combined with deep plowing and ripening the soil. This is a better method of fertilization.
5、Fertilization of the whole garden
For adult loquat orchards, the root system of loquat trees has covered the whole garden. We can spread the fertilizer evenly throughout the garden and then turn it into the soil. When we fertilize the whole garden, we can make better use of the fertilizer if we combine strip fertilization or radial furrow fertilization. This method of fertilization is shallow and easy to make the loquat root system move up.
6、External root fertilization
Also known as foliar spray fertilizer. External root fertilization is a method of dissolving fertilizer in water and spraying it directly onto the leaves of loquat trees so that the leaves can directly absorb and utilize the nutrients. This method is simple and easy to implement, with small amount of fertilizer and fast absorption and utilization. It has an important role in preserving flowers and fruits, promoting fruit development, improving quality, correcting deficiency, improving fertilization efficiency and regulating loquat tree potential. However, the role of extra-root fertilizer is short and can only play a supplementary role, and cannot completely replace soil fertilization.
① Root fertilization
The period of root set fertilization should be in the root growth and absorption period. The effect is better in 5~7 days after flowering. The concentration of application, generally slightly lower than the concentration of fertilizer used outside the root. The method is to use a 10-15 cm plastic bag with 100-200 ml of fertilizer solution. Then pull out a bunch of new roots with more fibrous roots at about 30~50 cm inside the east, south, west and north drip lines of the loquat canopy. Insert it into a plastic bag filled with fertilizer and tie the bag to prevent water evaporation. This method is more effective in correcting deficiency.
②Drip irrigation fertilization
Drip irrigation fertilization method, is also an advanced fertilization and irrigation technology. It has the advantages of timely fertilizer supply, even distribution of fertilizer, no root injury, protection of soil structure, less labor and less fertilizer dosage, etc. Simple drip irrigation method: Use a plastic bag that can hold 30~40 kg of water and a drip tube of 3 mm plastic pipe. We control the water output with wire ties, about 110~120 drops per minute. Set up 3~5 water bags per plant and bury the drip tube in 20~30 cm of soil.