Tea Tree Fertilization Techniques Part 2: Detailed Explanation of Methods and Key Points
Tea Tree Fertilization Techniques (Part 2)
(3) Placement of base fertilizer.
The placement of base fertilizer should be determined based on factors such as tree age and tea garden topography. The basic principle is to apply it near the tea tree root system, so as to facilitate root absorption and reduce nutrient loss. For 1- to 2-year-old tea gardens, the tea tree roots grow horizontally within a range of about 10 cm and at a depth of 15-20 cm; base fertilizer should be applied 10-15 cm from the root collar and at a depth of 10-15 cm. For 3- to 4-year-old tea gardens, the tea tree roots occupy a horizontal range of 20-30 cm of soil; base fertilizer should be applied 20-25 cm from the root collar and at a depth of 20-30 cm. For mature tea trees, most absorbing roots are distributed within the 20-40 cm soil layer, so base fertilizer can be applied at a depth of about 20 cm directly below the vertical line of the canopy edge. In the South China tea region, where temperatures are high and rainfall is heavy, nutrient leaching is strong, so base fertilizer can be applied somewhat shallowly, preferably below the dense root layer.
3. Topdressing.
Fertilizers applied during the aboveground growth period of tea gardens are collectively called tea garden topdressing. Their purpose is to continuously replenish the nutrients needed by tea trees, further promote tea tree growth, and achieve sustained high quality and high yield. The timing of topdressing is generally chosen before the start of each tea season, divided into spring, summer, and autumn tea topdressing. During vigorous growth, tea trees have a strong and rapid ability to absorb nutrients, so topdressing should mainly use quick-acting chemical fertilizers, commonly including urea, ammonium bicarbonate, and ammonium sulfate. On this basis, phosphate, potassium, and trace element fertilizers should be applied in combination, or compound fertilizer can be used as topdressing.
(1) Timing of topdressing.
This is divided into spring tea topdressing and summer and autumn tea topdressing. In spring, tea trees grow vigorously, have a strong ability to absorb nutrients, and require a large amount of nutrients. Spring tea accounts for a large proportion of the annual tea yield and also has good quality; most famous and high-quality teas come from spring tea. Topdressing before spring tea is commonly called bud-promoting fertilizer and is especially important for the production of famous and high-quality spring tea. Experiments by Wu Xun and Ru Guomin (1986) in the Hangzhou tea region showed that applying bud-promoting fertilizer on February 13 significantly increased the sprouting density and hundred-bud weight of spring tea compared with application on March 13, and the yields of spring tea and pre-Grain Rain Longjing tea increased by 11% and 18%, respectively. Therefore, bud-promoting fertilizer should be applied at an appropriate time according to the nutrient absorption patterns of tea trees, specifically depending on the early spring climate conditions of that year and the tea tree variety; generally, it can be applied about 30 days before spring tea picking. For tea gardens that mainly produce famous and high-quality tea and have relatively high yields, spring tea picking is intensive, so it may be considered to add one nitrogen fertilizer topdressing when spring tea picking begins after applying bud-promoting fertilizer.
After vigorous spring growth and multiple pickings, tea trees have consumed a large amount of nutrients. To ensure normal growth of summer and autumn tea, nutrients need to be replenished in time. Before spring tea ends and summer tea begins to grow, a second topdressing, namely summer fertilizer, is needed. The interval between spring tea and summer tea is relatively short, so summer fertilizer is generally applied immediately after spring tea ends. After summer tea ends, a third fertilization is carried out to favor autumn tea growth.
(2) Number of topdressings and allocation ratio.
In the South China tea region, temperatures are high and rainfall is abundant, the tea tree growth period is long, and there are many rounds of sprouting, so the corresponding number of fertilizer applications is also greater, sometimes reaching 5-6 times. It should be noted that the number of fertilizer applications should not be too many either; on the one hand, this increases fertilization labor, and on the other hand, it also makes the fertilizer too dispersed, making it easy for each round of new shoot growth to lack fertilizer at its peak. The allocation ratio of topdressing mainly depends on factors such as the biological characteristics of tea trees, the picking system, and climatic conditions. Taking the Yingde tea region as an example, mature tea gardens are topdressed 4-5 times per year, applied 10-15 days before each round of sprouting, mainly with quick-acting nitrogen, with a furrow application depth of 10-15 cm and an N:P:K fertilizer ratio of 4:1:1. If the yield of dry tea is below 100 kg per mu, apply 10 kg of pure nitrogen; if the yield of dry tea is 150-200 kg per mu, apply 15-20 kg of pure nitrogen. Thereafter, as yield increases, for every additional 100 kg of dry tea produced, apply an additional 15 kg of pure nitrogen, along with corresponding phosphate and potassium fertilizers, which can increase yield and improve quality with relatively good economic benefits.
The placement of base fertilizer should be determined based on factors such as tree age and tea garden topography. The basic principle is to apply it near the tea tree root system, so as to facilitate root absorption and reduce nutrient loss. For 1- to 2-year-old tea gardens, the tea tree roots grow horizontally within a range of about 10 cm and at a depth of 15-20 cm; base fertilizer should be applied 10-15 cm from the root collar and at a depth of 10-15 cm. For 3- to 4-year-old tea gardens, the tea tree roots occupy a horizontal range of 20-30 cm of soil; base fertilizer should be applied 20-25 cm from the root collar and at a depth of 20-30 cm. For mature tea trees, most absorbing roots are distributed within the 20-40 cm soil layer, so base fertilizer can be applied at a depth of about 20 cm directly below the vertical line of the canopy edge. In the South China tea region, where temperatures are high and rainfall is heavy, nutrient leaching is strong, so base fertilizer can be applied somewhat shallowly, preferably below the dense root layer.
3. Topdressing.
Fertilizers applied during the aboveground growth period of tea gardens are collectively called tea garden topdressing. Their purpose is to continuously replenish the nutrients needed by tea trees, further promote tea tree growth, and achieve sustained high quality and high yield. The timing of topdressing is generally chosen before the start of each tea season, divided into spring, summer, and autumn tea topdressing. During vigorous growth, tea trees have a strong and rapid ability to absorb nutrients, so topdressing should mainly use quick-acting chemical fertilizers, commonly including urea, ammonium bicarbonate, and ammonium sulfate. On this basis, phosphate, potassium, and trace element fertilizers should be applied in combination, or compound fertilizer can be used as topdressing.
(1) Timing of topdressing.
This is divided into spring tea topdressing and summer and autumn tea topdressing. In spring, tea trees grow vigorously, have a strong ability to absorb nutrients, and require a large amount of nutrients. Spring tea accounts for a large proportion of the annual tea yield and also has good quality; most famous and high-quality teas come from spring tea. Topdressing before spring tea is commonly called bud-promoting fertilizer and is especially important for the production of famous and high-quality spring tea. Experiments by Wu Xun and Ru Guomin (1986) in the Hangzhou tea region showed that applying bud-promoting fertilizer on February 13 significantly increased the sprouting density and hundred-bud weight of spring tea compared with application on March 13, and the yields of spring tea and pre-Grain Rain Longjing tea increased by 11% and 18%, respectively. Therefore, bud-promoting fertilizer should be applied at an appropriate time according to the nutrient absorption patterns of tea trees, specifically depending on the early spring climate conditions of that year and the tea tree variety; generally, it can be applied about 30 days before spring tea picking. For tea gardens that mainly produce famous and high-quality tea and have relatively high yields, spring tea picking is intensive, so it may be considered to add one nitrogen fertilizer topdressing when spring tea picking begins after applying bud-promoting fertilizer.
After vigorous spring growth and multiple pickings, tea trees have consumed a large amount of nutrients. To ensure normal growth of summer and autumn tea, nutrients need to be replenished in time. Before spring tea ends and summer tea begins to grow, a second topdressing, namely summer fertilizer, is needed. The interval between spring tea and summer tea is relatively short, so summer fertilizer is generally applied immediately after spring tea ends. After summer tea ends, a third fertilization is carried out to favor autumn tea growth.
(2) Number of topdressings and allocation ratio.
In the South China tea region, temperatures are high and rainfall is abundant, the tea tree growth period is long, and there are many rounds of sprouting, so the corresponding number of fertilizer applications is also greater, sometimes reaching 5-6 times. It should be noted that the number of fertilizer applications should not be too many either; on the one hand, this increases fertilization labor, and on the other hand, it also makes the fertilizer too dispersed, making it easy for each round of new shoot growth to lack fertilizer at its peak. The allocation ratio of topdressing mainly depends on factors such as the biological characteristics of tea trees, the picking system, and climatic conditions. Taking the Yingde tea region as an example, mature tea gardens are topdressed 4-5 times per year, applied 10-15 days before each round of sprouting, mainly with quick-acting nitrogen, with a furrow application depth of 10-15 cm and an N:P:K fertilizer ratio of 4:1:1. If the yield of dry tea is below 100 kg per mu, apply 10 kg of pure nitrogen; if the yield of dry tea is 150-200 kg per mu, apply 15-20 kg of pure nitrogen. Thereafter, as yield increases, for every additional 100 kg of dry tea produced, apply an additional 15 kg of pure nitrogen, along with corresponding phosphate and potassium fertilizers, which can increase yield and improve quality with relatively good economic benefits.