Currently, about 20,000 hectares of orchards in the north of the country are under tea cultivation. In tea gardens, due to the operations of porcelain leaves, pruning, erosion and leaching, a large amount of nutrients in the soil is reduced, which is compensated by the use of agricultural fertilizers to reduce the nutrients needed for plant growth. Otherwise, the tea garden soil gradually loses its fertility and results in a low quality product. In general, the substances that are added to agricultural lands for soil fertility are called fertilizers. Agricultural fertilizers are usually classified into livestock, green manure, municipal waste and chemicals. According to studies conducted in research centers inside and outside the country, with the harvest of about five tons of green tea per hectare, the amount of 50-60 kg of nitrogen, 25-30 kg of potassium, 8-10 kg of phosphorus from food reserves of garden soil Tea is reduced annually.
Suitable soils for growing tea:
Tea is grown in a wide variety of soils, but the tea plant prefers light soils rich in organic matter. Shrubs also need a lot of moisture. In soils under tea cultivation, the groundwater level should be lower than 90 cm. If the amount of rainfall is high and the soil is very heavy, cultivation restrictions will occur.
In general, tea is a plant that performs better in acidic soil. It grows better in soils with a pH of about 4.5-5.5. Because tea requires a lot of aluminum and manganese, this is why the tea plant tends to have a low pH. However, it should be noted that the pH should not fall below 4.5 in tea plantations, because under these conditions, the roots suffer damage and negatively affect plant yield.
Tea plant nutrition:
Macro fertilizers have been widely used in recent years to feed tea gardens and provide high-nutrient nutrients. The guidelines that are usually recommended and followed in rainfed and irrigated gardens are summarized in the table below.
Of course, in orchards that are irrigated, micronutrients (zinc sulfate and copper sulfate) are sprayed at a rate of 5 per thousand, 2 to 3 times after emergence. Of course, the use of micronutrient fertilizers is not yet common in tea gardens
Problems in feeding tea gardens:
One of the problems that has occurred in recent years in tea farms in the north of the country is the acidification of about half of the soils of tea gardens whose soil pH has been less than 4 (optimal pH for tea gardens is 5.5 to 4.5. Low pH yields and yield of tea gardens are reduced, aluminum poisoning occurs in the soil, and as a result, conditions are provided for the activity of tea root wound nematodes (according to available statistics, unfortunately, about two thirds of tea gardens are infected with nematodes. One of the reasons is the low pH of the soil.) To solve the problem of acidification of the soil of tea gardens, the correct formula of fertilizer should be used in the gardens. In the first step to improve the soil of tea plantations, it is recommended to add calcareous modifiers to the soil in late winter. One of the modifiers is dolomite limestone, which is very suitable for drinking tea due to its magnesium content.
