Tea is a perennial cash crop for harvesting young shoots and leaves. The new green nutritious shoots have to be picked from the tea leaves several times a year. This is extremely nutrient-depleting to the tea leaves. At the same time, tea itself requires constant construction of nutrient organs such as roots, stems and leaves. This allows the tree to maintain its prosperity, continue to expand and regenerate long, as well as flowering and fruiting to reproduce offspring. This all consumes a large amount of nutrients. Therefore, a reasonable supplement must be given at the right time to meet the robust growth of tea. Make it high-quality, stable and high-yielding.
A、The nutrients required for tea
The mineral elements necessary for tea fertility are: nitrogen, phosphorus, potassium, calcium, iron, magnesium, sulfur and other massive elements and manganese, zinc, copper, boron, molybdenum, aluminum, fluorine and other trace elements. Production practice and scientific research shows that the lack of magnesium and zinc in the tea garden is relatively common.
Nitrogen is an important part of the synthesis of protein and chlorophyll. The application of nitrogen fertilizer can promote the growth of tea roots, so that the branches and leaves flourish. It also promotes the absorption of other nutrients and improves the photosynthetic efficiency of tea leaves, etc. When nitrogen supply is sufficient, tea leaves germinate more, new growth is faster, internodes are longer, leaves are more, leaf area is larger and holding period is longer. It can also inhibit reproductive growth, thus improving the yield and quality of fresh leaves.
Phosphorus fertilizer can mainly promote the development of it root system. It enhances the absorption of nutrients by tea leaves, promotes starch synthesis and improves the physiological function of chlorophyll. Thus, it can improve the content of tea polyphenols, catechins, proteins and water leachables in tea leaves. It can improve tea quality in a more comprehensive way. Phosphorus deficiency in tea leaves is often not easily detected in a short period of time. It takes even a few years before it manifests itself. The symptoms are: new shoots and leaves are yellow and thin, internodes are not easy to elongate, old leaves are dark green and lusterless, and then withered and fallen off, the root system is dark brown.
Potassium has a positive effect on the formation, transformation and storage of carbohydrates. It can also supplement insufficient sunlight and promote photosynthetic assimilation in low light. It promotes root development, regulates water metabolism and enhances resistance to frost and pests and diseases. In case of potassium deficiency, the lower leaves of tea become old early and fall off early, the tea branches are sparse and slender, and the crown does not develop. Young leaves scorched edge and accompanied by irregular lack of green, so that the tea leaves resistance to pests and other natural disasters is reduced.
B、The tea leaves on the absorption time of fertilizer
Tea leaves in the different cycles of annual development of the demand for nutrients are not consistent. According to research data, the uptake of nitrogen in a year is more from April to June, July to August, September and October to November. And the absorption of the first two periods accounted for more than 55% of the total nitrogen uptake throughout the year.
1、Tea absorption of phosphorus time
Phosphorus uptake is mainly concentrated in April to July and September. The absorption of potassium is the most from July to September. In addition, the requirements of each organ of it leaves for the three elements in different periods also differ somewhat. For example, tea roots need nitrogen mainly from September to November. Stems in July to November, these two seasons account for about 60% to 70% of the total annual uptake.
2、Tea absorption of nitrogen time
The amount of nitrogen requirements of tea leaves, April to September to be 80% to 90% of the total amount of the year. Tea root demand for phosphorus, the peak period is from September to November, the stem is in September. Leaves, buds and other organs are in April to October. Among them, the demand in July is the most.
3、The time of tea absorption of potassium
The demand for potassium by the root system of it is mainly from September to November. It accounts for about 50% to 60% of the year. Stems in April to September, with the highest demand in September.
From the above tea demand for nitrogen, phosphorus and potassium in different seasons, we need to apply the right amount of fertilizer at the right time. This is also an important way to improve the utilization rate of various types of fertilizers.
C、The characteristics of tea fertilizer needs
1、The need for fertilizer continuity
Tea is a perennial plant. In the annual growth and development cycle, most of the period is in the buds and leaves picking. And constantly consume nutrients. Because of the various fertility stages of it throughout the year, its body is carrying out metabolic activities, never interrupted. Therefore, the nutritional condition of it leaves is not only closely related to the yield and quality of the year. Moreover, it will also affect the production and quality performance of the coming year. Therefore, the demand of it for nutrients is continuous.
2、Stage of fertilizer requirement
In the different stages of tea development and growth, the demand and absorption of various nutrients are focused. For example, the tea leaves in the juvenile period are dominated by the growth of nutrient organs. The growth of the upper part of the branches exceeds that of the lower part of the root system. Synthesis is more than decomposition. Therefore, we need to appropriately increase the application of phosphorus and potassium fertilizer to lay the foundation for future growth and development.
Tea leaves in the young and strong stage. As nutritional growth and reproductive growth go hand in hand. We need to make a large amount of additional nitrogen fertilization. Promote a large number of sprouting leaves, and use phosphorus and potassium and a variety of elements to promote high yield and quality.
3、Concentration of fertilizer requirement
In the annual development cycle, due to seasonal changes and its own physiological activity phenomenon, and the formation of a period of vigorous growth and growth of the relative rest period. Mature tea plantations also due to harvesting and other relationships so that the shoot tip growth formed a more obvious round. In the peak growth period and each round of young buds and leaves are picked. In order to match the needs of normal growth, we need to provide a large amount of nutrition. Among the three elements, the need for nitrogen is the most, followed by potassium and the least phosphorus.
4、The need for fertilizer adaptability
Tea has a wide range of adaptation to nutritional conditions. First of all, it is manifested in the diversity of nutrient requirements. Tea in the process of growth and development, the demand for nutrients. In terms of quantity, although the three elements of N, P and K are dominant. However, in addition to this, some trace elements Mn, Fe, Zn, B, Al, Cu on the normal physiological activities of it also have a great impact. As long as some elements are lacking, they will interfere with and disrupt the normal metabolism of tea. And produce physiological lesions, and lead to a decline in yield and quality.
On the other hand, tea leaves are highly fertilizer tolerant and barren. Take the application of nitrogen fertilizer as an example. For each hectare of it garden, we apply a minimum of 50㎏ of pure nitrogen fertilizer and a maximum of 1000㎏. Although the difference between the two amounts of 20 times, but no harm to tea. It is thus clear that it does have a greater adaptability to nutrition.