Fertilization Technology of Tea Plant (part two)

(3) the location of base fertilizer application.

The location of base fertilizer application should be determined according to the factors such as tree age and tea garden topography. The basic principle is to apply it near the tea root system to facilitate root absorption and reduce nutrient loss. The horizontal growth range of tea root system in 1-year-old tea garden is about 10 cm, and the depth is 15 cm. The base fertilizer is applied at 10 cm from the root neck and 10 cm to 15 cm deep. The horizontal growth range of tea root system in 3-4-year-old tea garden is 20 cm 30 cm soil layer, and the base fertilizer is applied in the soil layer 20 cm 25 cm from the root neck and 20 cm deep. Most of the absorbing roots of adult tea trees are distributed in the soil layer of 20 cm to 40 cm, and the base fertilizer can be applied at a depth of about 20 cm below the edge of the crown. In the tea area of South China with high temperature and heavy rainfall, the leaching of nutrients is strong, and the base fertilizer can be applied shallowly, which is better below the dense layer of root system.

3. Topdressing.

The fertilizer applied during the aboveground growth of tea garden is commonly known as tea garden topdressing, and its purpose is to continuously supplement the nutrients needed by tea trees, so as to further promote the growth of tea trees and achieve the goal of sustainable high quality and high yield. The time of topdressing is generally chosen before the beginning of each tea season, which is divided into spring, summer and autumn tea. During the vigorous growth period, tea trees have strong ability to absorb nutrients and absorb quickly, so topdressing should be based on quick-acting chemical fertilizer, such as urea, ammonium bicarbonate and ammonium sulfate, on this basis, phosphorus, potash and trace element fertilizers are applied, or compound fertilizer is used as topdressing.

(1) topdressing time.

It is divided into spring tea topdressing and summer and autumn tea dressing. Tea plants grow vigorously in spring, have a strong ability to absorb nutrients, and need a large amount of nutrients. Spring tea accounts for a large proportion of tea output in the whole year, and the quality is good, and most of the famous and high-quality tea comes from spring tea. Topdressing before spring tea is commonly known as sprouting fertilizer, which is particularly important for the production of famous and high-quality tea in spring. The experiment of Wu Yan and Ru Guomin (1986) in Hangzhou tea area showed that the germination density and 100 bud weight of spring tea were significantly higher than those on March 13, and the yield of spring tea and Grain Rain Qianlongjing tea increased by 11% and 18%, respectively. Therefore, budding fertilizer should be applied in an appropriate period according to the law of nutrient absorption of tea trees, depending on the climate of early spring and tea varieties, and can be applied about 30 days before spring tea picking. For the tea gardens with high yield and high yield of famous tea, the picking intensity of spring tea is high, so it can be considered to increase nitrogen fertilizer and topdressing once when spring tea is picked after budding fertilizer.

After vigorous growth and picking many times in spring, tea trees consume a lot of nutrients. In order to ensure the normal growth of summer and autumn tea, it is necessary to replenish nutrients in time, and the second topdressing, namely summer fertilizer, is needed before the end of spring tea and the beginning of summer tea growth. The interval between spring tea and summer tea is short, and summer fertilizer is usually applied immediately after the end of spring tea. The third fertilization was carried out after the end of summer tea to facilitate the growth of autumn tea.

(2) the times and distribution ratio of topdressing.

In the tea area of South China, the temperature is high, the rainfall is abundant, the growth period of tea tree is long, there are many times of germination, and the corresponding times of fertilization are also many, sometimes up to 5-6 times. It should be noted that the number of fertilization should not be too much, on the one hand, increase the labor of fertilization, but also make the fertilizer too dispersed, easy to make each round of new shoot growth in the peak period of lack of fertilizer. The distribution proportion of topdressing mainly depends on the biological characteristics of tea trees, picking system, climatic conditions and other factors. Taking Yingde tea area as an example, the adult tea garden was topdressing 4-5 times a year and applied 10-15 days before each round of germination, mainly available nitrogen, the furrow application depth was 10-15 cm, and the ratio of nitrogen, phosphorus and potassium fertilizer was 4:1:1. For example, dry tea per mu is less than 100 kg, pure nitrogen is 10 kg, dry tea is 150-200 kg per mu, and pure nitrogen is 15-20 kg per mu. In the future, with the increase of yield, the application of 15 kg pure nitrogen and corresponding phosphorus and potassium fertilizer for every 100 kg dry tea can increase the yield and improve the quality, and the economic benefit is better.