The main goal is to improve the soil condition, increase nutrient availability, and create favorable conditions for Tea plant growth, with tasks including soil cultivation, weeding, fertilization, and moisture retention.
I. Garden Cultivation
Reasonable cultivation is an important measure to improve the soil condition in tea gardens, which can enhance the micro-ecological environment of the soil and provide good conditions for the growth and development of tea plants, improving their vigor.
1. Shallow Cultivation and Weeding
The purpose of shallow cultivation in tea gardens is to remove weeds, loosen the surface soil, and improve the micro-ecological environment of the surface soil layer. The depth of shallow cultivation is generally around 5 cm, and it can be combined with top-dressing and soil mounding. It's also essential to clear weeds and brambles around the tea garden promptly. For young tea gardens that are not yet closed row, cultivation should be done whenever weeds appear, requiring six to seven weedings per year.
Since the Root system of young tea gardens does not penetrate deeply in the planting year, shallow cultivation before the high-temperature season should be done early to avoid drought immediately after cultivation. For mature tea gardens, cultivation is divided into spring, post-spring, and summer-autumn cultivation. During spring and summer shallow cultivation, dead branches and leaves near the root neck should be cleared and placed between rows to decompose; during autumn and winter shallow cultivation, the roots should be covered with fertile soil to prevent frost damage.
2. Deep Cultivation and Soil Turning
Young tea gardens do not need deep cultivation in the planting year since they have already been deep cultivated before planting. Mature picking tea gardens are generally deep cultivated in autumn and winter, combined with the application of organic fertilizers, alternating rows and years. For tea gardens undergoing renovation, deep cultivation can be combined with base fertilizer application. The depth of deep cultivation is generally around 10 cm, with a width of no less than 20 cm, and the depth slightly increased when combined with base fertilizer application. Deep cultivation should not be too close to the root neck of the tea plants, starting from the outer edge of the tea canopy.
3. Covering and Moisture Retention
Ground covering in tea gardens is an important management technique for moisture retention. Covering materials can include Rice straw, chaff, wood chips, green grass, pruned tea branches, and weeds from garden cultivation. The thickness of dry straw should not exceed 1.5 cm, and fresh wood chips should not exceed 3 cm. Newly planted tea gardens should be covered at planting, while mature tea gardens should be covered before the onset of severe cold or high temperatures and drought. Grasses are generally laid between rows without being pressed down, while finer materials like chaff should be covered with soil after application to prevent them from being blown away or washed away by rain. Garden weeds should be turned over to prevent regrowth.
II. Fertilization in Tea Gardens
As a special group of genotypes, albino tea has specific requirements for fertilizers. Excessive use of fast-acting chemical fertilizers can increase chlorophyll content, leading to insufficient albinism or premature return to green; insufficient fertilization or excessive reliance on organic fertilizers can increase the ratio of phosphorus and potassium, enhancing reproductive growth and causing excessive flowering, affecting yield improvement.
(a) Fertilization Principles
In addition to following the principles of “highlighting organic fertilizers, increasing fertilization amounts, increasing the proportion of base fertilizers, and emphasizing green safety,” fertilization in albino tea gardens must also consider its impact on the balance between “albinism-return to green” and “reproductive-nutritional” growth. Choosing fertilizers based on species and tree conditions is crucial.
1. Control Nitrogen Fertilizer Use Before Spring Tea in Mature Gardens
After using inorganic fertilizers, especially nitrogen fertilizers, varieties like Baiye No. 1 often fail to turn white or show insufficient albinism or return to green prematurely. Therefore, mature tea gardens should primarily use organic fertilizers and limit the use of chemical fertilizers. Since only spring tea is harvested, the entire year's fertilization should consist of base fertilizers, and the timing should be advanced to autumn or even after the end of spring tea harvesting and pruning; within the juvenile period, there's no need to worry about affecting albinism, and nitrogen fertilizers can promote new Shoot development, so their use is not restricted.
2. Control Phosphorus and Potassium Fertilizer Use
The reproductive growth of albino tea occurs earlier than conventional varieties, and the use of organic fertilizers with a high phosphorus-potassium ratio can lead to flowering and fruiting. Generally, increasing nitrogen fertilizer usage can meet the needs of enhancing tree vigor; for varieties that are not sensitive to fertilizer types, methods similar to those used for conventional varieties can be adopted.
(b) Fertilization Amounts
The fertilization amount for mature albino tea gardens is based on the same age as conventional variety tea gardens. The annual fertilization amount for gardens producing bulk tea is typically determined by applying 10 to 15 kg of pure nitrogen per 100 kg of dried tea produced in the previous year, with a ratio of nitrogen, phosphorus, and potassium of 4:1:1. The proportions of winter base, spring top-up, and summer-autumn fertilizers are 4:3:3. Considering the potential for increased production, it is recommended to apply 100 to 150 kg of rape Cake per mu as base fertilizer, which can meet the growth requirements of tea plants.
Producing 100 kg of dried tea in bulk tea gardens is equivalent to 5 kg of spring specialty tea in albino tea gardens. Based on this, albino tea gardens should apply 2 to 3 kg of pure nitrogen per kilogram of dried tea produced. Considering that albino tea gardens only harvest spring tea, excessive nitrogen fertilizers can cause insufficient albinism, while the exclusive use of organic fertilizers can result in vigorous reproductive growth. Therefore, in addition to proper seasonal scheduling, fertilization in albino tea gardens should prioritize organic fertilizers and supplement with chemical fertilizers. The proportions of winter base, spring top-up, and summer-autumn fertilizers should be 6:2:2. Generally, the fertilization level should be controlled at 150 to 200 kg of rape cake per mu, with the level of organic fertilizers slightly higher than that of conventional variety tea gardens.
(c) Fertilization Methods
Fertilization in tea gardens is divided into base fertilizers and top-up fertilizers, mainly solid fertilizers, but liquid fertilizers are encouraged where feasible.
1. Base Fertilizer
The application of base fertilizers should follow the principle of “appropriate deep application.” They should generally be applied at a depth of 10 to 20 cm near the root system of the tea plants. In flat land tea gardens, trenches should be dug along both sides under the canopy, or alternated each year on one side of the canopy. In sloping tea gardens, fertilizers should be applied in trenches above the tea rows, and in terraced tea gardens, the trenches should be on the inside.
For newly planted albino tea gardens without base fertilizers, a base fertilizer should be applied in autumn after planting. The type of fertilizer should be rape cake or commercial organic fertilizer with fewer pathogenic fungi, with an amount of about one-third of that used in mature gardens, supplemented with 20 kg of compound fertilizer, applied in trenches 20 cm away from the roots. In the second year, the fertilizer amount can be increased to half of that used in mature gardens, and the type of fertilizer can be the same as that used in mature gardens. For newly planted albino tea gardens that have received base fertilizers, organic fertilizers do not need to be applied in autumn after planting, but 20 kg of compound fertilizer should be added. Starting in the second year, base fertilizers can be applied, with the amount reaching half of that used in mature gardens, and the type of fertilizer can be the same as that used in mature gardens.
2. Top-Up Fertilizer
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