How to fertilize pomegranate trees without pollution? Detailed technical points
How to fertilize pomegranate trees without pollution? Please provide guidance. For pollution-free fertilization of pomegranate trees, you can refer to the following methods: 1. Fertilization timing. The key to whether the fertilization timing is scientific and reasonable lies in seizing the several critical periods of fertilizer demand during the growth and development of pomegranate trees. Pomegranate fertilization is divided into base fertilizer and topdressing. Base fertilizer generally...
How to fertilize pomegranate trees without pollution? Please provide guidance
For pollution-free fertilization of pomegranate trees, you can refer to the following methods:
I. Fertilization timing
The key to whether the fertilization timing is scientific and reasonable lies in seizing the several critical periods of fertilizer demand during the growth and development of pomegranate trees. Pomegranate fertilization is divided into base fertilizer and topdressing. Base fertilizer generally uses high-quality organic fertilizer, which can provide various nutrient elements to pomegranate trees in a balanced way throughout the year. Base fertilizer is best applied in autumn, combined with deep soil ploughing. At this time, it coincides with the second growth peak of pomegranate roots; many new roots emerge, growth is fast, cut roots heal and regenerate easily, and the white absorbing roots produced can absorb part of the nutrients, which helps restore tree vigor and increase reserve nutrients. Moreover, most of the organic matter is fully decomposed in the soil and can be absorbed and utilized during the flowering and budding period of pomegranate in spring.
The determination of topdressing timing is mainly based on the progress of phenological periods and the needs of growth and fruiting to carry out timely nutrient supplementation. (1) Topdressing before budding and after flowering: mainly to supplement the deficiency of stored nutrients, improve fruit set rate and new shoot growth, with compound fertilizer as the main type. (2) Topdressing during the swelling period: to promote new shoot growth and flower bud differentiation, apply an appropriate amount of nitrogen fertilizer, with more phosphorus and potassium fertilizer, mainly ternary compound fertilizer. (3) Topdressing before harvest: mainly quick-acting potassium fertilizer, which can promote fruit swelling and improve fruit quality, generally applied 15 days before harvest. (4) Topdressing after harvest: mainly for varieties that consume more nutrients or trees with weakened vigor, which can strengthen tree vigor and increase reserve nutrients.
II. Reasonably determine the fertilization amount
1. Organic fertilizer serves as the basic fertilizer for pollution-free pomegranate. From the fertilization level of pomegranate production in our region, the amount of organic fertilizer applied per mu in pollution-free pomegranate production should be 4000-5000 kg, while the amount used in production is only 600-800 kg per mu. Organic fertilizer application is seriously insufficient, which increases the application amount of chemical fertilizers. This is also one of the reasons for the decline in pomegranate quality. Organic fertilizer can improve the soil, increase soil capacity, reduce environmental pollution, and significantly improve pomegranate yield and quality.
2. Soil testing and formula fertilization. Soil testing fertilization plays a great role in improving fruit set rate and maintaining sustained and stable yield increases. The determination of soil testing fertilization amount should not only consider factors such as the nutrient demand for growth of the pomegranate orchard, fertilizer utilization rate and pomegranate growth conditions, but also require comprehensive analysis and appropriate increase or decrease. According to measurements, for a pomegranate orchard with a yield of 2300 kg per mu, the more suitable amounts and combination ratio of nitrogen, phosphorus and potassium are: pure nitrogen 21.2 kg/mu, pure phosphorus 18.4 kg/mu, pure potassium 9.6 kg/mu, with N:P2O5:K2O being 14:18:18. However, the suitable formula ratio is related to pomegranate yield and soil N, P, K nutrient content. Therefore, the suitable amount of various fertilizers should be determined according to the yield and level of different pomegranates and the fertilizer supply capacity of the soil.
III. Fertilization methods
Scientific fertilization should be carried out according to the fertilizer demand characteristics of pomegranate and the characteristics of various chemical fertilizers. Young trees use ring-shaped trench application, with the position at the outer edge of the tree crown; trees in full fruiting stage use radial trench application. According to the root distribution, the radial trenches should be dug shallow on the inside and deep on the outside. The end near the central trunk is about 10-20 cm, and the end far from the central trunk is about 30-40 cm. For clay soil that is hard and has strong fertilizer retention, deeper application can be carried out appropriately to guide roots to expand deeper, while sandy soil loses nutrients easily, so shallow application is suitable. The position of radial trenches should be changed every year to achieve the purpose of improving soil throughout the orchard.
IV. Scientifically combined application of micro-fertilizers
With the continuous increase of pomegranate yield and the repeated use of old pomegranate orchards, a large number of nutrient elements are taken away from the soil every year, resulting in the deficiency of some trace elements. At present, due to the deficiency of trace elements such as zinc and boron in pomegranate orchards in various places, the quality and yield of pomegranate have been affected. When pomegranate is deficient in zinc, spring sprouting is later, fine leaves are clustered, leaves are small, flower buds are reduced, fruiting is difficult, fruits are small, the root system of young diseased trees develops poorly, the root system of old diseased trees has rotting phenomena, the tree crown is sparse and cannot expand, and the yield is very low. Preventive measures: (1) Soil application method: combined with fertilization, apply 0.1 kg zinc sulfate per tree. This method has a long effective period. (2) Foliar spraying: spray zinc sulfate solution 1-2 times 2-3 weeks before flowering. The preparation ratio of zinc sulfate solution is 36%, that is, zinc sulfate 1 kg, quicklime 0.7 kg, water 200 kg. This method can not only reduce the production of small fruits, but also improve the fruit set rate. When pomegranate orchards are deficient in boron, irregular necrosis appears at the top shoots in the initial stage, and upper leaves turn yellow. With moderate deficiency, the terminal buds die and growth stops. In the final stage, the top shoots wither. Preventive measures: around the beginning of flowering, 1220.2% borax or 0.1% boric acid can be sprayed as foliar fertilizer 2-3 times; borax 20 g per tree can also be applied combined with fertilization. When micro-fertilizers are applied to the roots, they should generally be combined with spring or autumn fertilizer application, and care should be taken not to apply too much to avoid fertilizer damage.
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