What kind of fertilizer is used for seedlings? How should fertilizer be applied? How to get fat?

A seedling is a sapling with roots and stems. Nursery stock concentrated production areas are distributed throughout the country. There are many kinds of seedlings, which have good economic benefits. The fertilizers used by different seedlings are also different. There are also many key points in fertilization and topdressing technology.

1. Fertilizer for seedlings

Fertilizers are usually divided into two categories: organic fertilizers and inorganic fertilizers.

Organic fertilizer is also called farm manure. Including human and livestock manure, compost, green moon, peat (peat), humus fertilizer and so on. It is characterized by many kinds, wide sources, complete nutrients, not only rich in a large number of elements nitrogen, phosphorus, potassium, but also contains trace elements, hormones and antibiotics, etc., can improve the physical and chemical properties of the soil, fertilizer release slow and lasting, is to improve soil fertility, improve the quality and yield of ornamental seedlings indispensable fertilizer.

Inorganic fertilizer is also called chemical fertilizer. include nitrogen fertilizer (ammonium sulfate, ammonium bicarbonate, ammonium nitrate, urea), potassium fertilize (potassium chloride, potassium sulfate, potassium dihydrogen phosphate), phosphorus fertilizer (calcium superphosphate, ammonium phosphate), trace element fertilizer (ferrous sulfate, boric acid). It is characterized by containing nitrogen, phosphorus, potassium and other nutrients in the state of inorganic compounds exist, nutrient single, high content, fertilizer efficiency, small size, easy to transport, and clean sanitation, easy to use.

Before application, we must understand the nature of various fertilizers and the characteristics of nutrient absorption by tree species, so as to apply fertilizer reasonably, improve the growth quality of seedlings and save fertilizer costs. Long-term single use of inorganic fertilizer will make soil hardening, the best combination of organic fertilizer application.

2. Fertilization method of seedling base fertilizer

Base fertilizer nursery soil fertility is generally poor, in order to improve the soil, base fertilizer is indispensable, sand land more needed. Generally often manure, compost, oil cake or manure and other organic fertilizers as base fertilizer, and more in the soil preparation before the spread, turning people in the tillage layer.

Calcium superphosphate and organic fertilizer mixed with the use of better results. Organic fertilizer must be decomposed and fermented, otherwise it will cause fertilizer damage. The amount of base fertilizer should be determined according to soil fertility and plant species, generally 150~200 kg of base fertilizer should be applied per 100 square meters of nursery land.

3. Top dressing method for seedlings

Topdressing is to supplement the deficiency of basal fertilizer to meet the needs of ornamental seedlings at different growth and development stages, and inorganic fertilizer (chemical fertilizer) is often used as topdressing.

(1) Look at the type of fertilizer

Nursery topdressing is generally used quick-acting fertilizer, such as plant ash, ammonium sulfate, urea, ammonium chloride, potassium chloride, etc. These fertilizers must be completely crushed and should not be applied in blocks. Organic fertilizers can also be applied, such as human and animal waste water, compost, etc., but they should be fully fermented and decomposed, and raw manure should not be used, and the concentration should be thin. Nitrogen fertilizer has strong mobility in soil and can be applied shallowly to penetrate into root distribution layer and be absorbed by seedlings; potassium fertilizer has poor mobility and phosphorus fertilizer has worse mobility, so it should be applied deeply to root distribution dense place.

(2) Fertilization depends on the weather

The frequency and amount of fertilization are determined according to weather conditions. Low temperature, less seedling absorption; high temperature, vigorous root growth, more fertilizer absorption. It is best to choose when the weather is clear and the soil is dry. On rainy days, due to the slow absorption of water by roots, not only nutrients are not easy to absorb, but fertilizer is also easily washed away by rain, resulting in waste. In dry days, it is best to use wet application method, that is, the fertilizer is applied to the nursery land evenly; moderate rainfall can be used dry application method, that is, the fertilizer is applied in the furrow, and the depth of furrow application should be in the distribution layer of roots to facilitate the absorption of fertilizer by seedlings.

(3) Look at the land and fertilize

Pay attention to the different types and quantities of nutrients contained in different soils and apply different types of fertilizers. Such as calcareous soil or strong acid nursery soil, easy to occur phosphorus deficiency, pay attention to increase phosphorus fertilizer, especially increase phosphorus fertilizer. Generally, the soil is dominated by nitrogen fertilizer. If the soil with sufficient nitrogen, the proportion of phosphorus and potassium fertilizer should be increased.

Different soil texture, nutrient conditions and fertilizer retention capacity are also different, so the fertilization methods are also different. Soil fertility retention ability is good, topdressing each time the amount can be more, the frequency can be less; soil fertility retention poor sandy soil nursery, topdressing frequency should be more and each time the amount should be less.

(4) seedling application

Seedling growth is generally divided into four stages: emergence stage, seedling stage, fast-growing stage and hardening stage.

Seedling can not produce nutrients by itself, its nutrition mainly depends on the nutrients stored in the seed; seedling stage refers to the emergence of true leaves on the ground part of the seedling, lateral roots on the ground part, until the seedling growth volume rises sharply, then it is sensitive to nitrogen and phosphorus; fast-growing stage is the simultaneous growth of the ground part and the underground part of the seedling, which requires a large amount of nutrients, so the amount of nitrogen fertilizer and the times should be increased, and phosphorus and potassium fertilizer should be applied in proportion. In order to promote seedling hardening and improve resistance, nitrogen fertilizer should be stopped in time at the later stage of growth, and to prevent excessive growth at the hardening stage, fertilizer should be stopped to improve seedling resistance. In general, annual seedlings need more nitrogen and phosphorus in the early stage of growth to promote the growth and development of young roots. In the fast-growing stage, they need a large amount of nitrogen, phosphorus, potassium and other elements. In the late stage of growth, potassium is the main element, and phosphorus is supplemented to promote the lignification of young stems. For the large-sized seedlings that have grown seedlings, the fertilization with strong roots and distant distribution should be deep and large, such as Pinus tabulaeformis, Ginkgo biloba, Albizzia sinensis, Ailanthus sinensis, etc.; the fertilization with shallow roots should be shallow and small, such as Pholonia formosana, Amorpha fruticosa and flowering shrubs.