When will pear trees be fertilized? Can nitramine be used as topdressing?

Pear trees have a long history of cultivation in China, which is recorded in the Book of Songs. It has been cultivated in China for at least 3000 years. In the process of pear cultivation, fertilization is an important factor to obtain high yield of pear. When making a fertilization plan, we should first understand the role of nutrients in pear growth and the law of pear fertilizer demand, and then we can make a scientific and reasonable fertilization plan. In the fertilization plan, I will talk about the fertilization time and types of pear trees.

1. Effects of nutrients on the growth and element deficiency disease shape of pear trees.

The growth and development of pear trees, like other fruit trees, need to constantly absorb nutrients from the soil to meet their own growth. The essential elements for the growth of pear trees are mainly nitrogen, phosphorus and potassium (nitrogen, phosphorus and potassium); Calcium, magnesium, zinc, iron, copper, boron and manganese (medium and trace elements).

Nitrogen: Nitrogen has an important influence on the growth, photosynthesis and protein synthesis of pear trees. When nitrogen is lacking, the leaves are thin and small, and the leaves turn yellow from top to bottom, so the trees will be stunted and the fruits will be reduced.

Phosphorus: Phosphorus plays an important role in promoting flower bud differentiation, early flowering and fruiting, seed maturity, sugar content and stress resistance. When phosphorus is lacking, the new shoots will be stunted first, and the leaves are small and purple, which is easy to fall off. There are few flowers and fruits, and the resistance of trees is weaker.

Potassium: Potassium plays an important role in promoting fruit ripening, improving fruit flavor, improving fruit storability and improving stress resistance of fruit trees. The growth and development of potassium-deficient branches are poor, the lower leaves appear yellowing and atrophy, the fruit is small and the quality is poor.

Calcium: Calcium plays a physiological balance role in peach trees and can promote the absorption of nitrogen and phosphorus by trees. Calcium deficiency will cause the top tender leaves to fade from top to bottom and turn brown.

Magnesium: Magnesium is an important component of chlorophyll, which affects the photosynthesis of pear trees. When magnesium is deficient, the leaves at the base of pear trees begin to turn green, and the leaves between veins turn green, resulting in macular mosaic. In severe cases, leaves will appear at the base of branches.

Second, the characteristics of pear tree fertilizer demand

The researchers found that pear trees in the fruiting stage generally do not produce 1 0,000 kg of pure nutrients, which are 4.5 kg of nitrogen, 0.9 kg of phosphorus, 3.7 kg of potassium, 4.4 kg of calcium and 0.3 kg of magnesium 1.3 kg, which provides an important basis for us to determine the fertilizer yield.

The fertilizer requirement characteristics of pear trees are somewhat similar to those of apple trees. Pear trees generally go through four stages from planting to death, namely, growth period, first fruit period, full fruit period and aging period.

Fertilizer requirement characteristics and growth period of 1

The period from transplanting to the first flowering and fruiting of pear trees is the growth period of pear trees, which generally takes about 3~4 years. This period is the stage of rapid growth of pear trees on the ground and underground, with the crown of the ground expanding and the branches thickening; The root system of the underground part is quickly fastened, creating suitable root conditions for later flowering and fruiting.

Fertilization in this period is mainly to promote the rapid vegetative growth of pear trees and grow branches and leaves quickly, so as to enter the fruiting period as soon as possible. Fertilization in this period should be based on organic fertilizer, but also with inorganic fertilizer, especially nitrogen fertilizer and phosphorus fertilizer.

2. Characteristics of fertilizer requirement at the first fruit stage.

At the initial stage of fruiting, the roots of branches and leaves on the ground and underground grow vigorously, and the roots on the ground continue to grow and expand the crown, which can form a small number of flower buds, and the yield will increase with the increase of tree age. The underground part is constantly expanding vertically and horizontally. At the initial fruit stage, the pear tree is strong, the pear fruit is big but the meat quality is rough, and the taste is not very good.

The purpose of fertilization in this period is still to promote the vegetative growth of plants, to expand the number of branches and leaves and the formation of main bearing branches, and to shorten the vegetative growth time as much as possible. In fertilization management, organic fertilizer should be added and nitrogen, phosphorus, potassium and trace elements should be supplemented appropriately.

3. Characteristics of fertilizer requirement in full fruit stage

At the full fruit stage, pear trees enter the fruit-rich stage, at the same time, the root system and crown skeleton have been formed during this period, and the yield has also entered a stable period. This is the time when pear trees need fertilizer most. Therefore, it is necessary to increase the amount of fertilization appropriately, and the phenomenon of large and small years can be effectively avoided by balanced fertilization.

4. The characteristics of fertilizer requirement in the process of aging.

During the aging period, the tree vigor gradually weakened, and the yield of fruit trees began to decline year by year. Fertilization in this period is mainly aimed at the growth of some fruiting branches, and the amount of nitrogen fertilizer should be increased to promote the vegetative growth and regeneration of fruiting branches, restore tree vigor and delay senescence.

Three. Annual Fertilization Scheme for Pear Trees in Fruiting Period

Scientific and reasonable fertilization is an important means to achieve high and stable yield. When fertilizing, targeted fertilization management should be carried out according to different tree ages and different growth stages. Let's talk about the fertilization management of pear trees in the full fruit period.

1, base fertilizer

Fertilization time: the fertilization time of base fertilizer is generally carried out after the fruit is harvested and before the pear leaves fall, which can be applied in conjunction with deep ploughing. Application amount of base fertilizer: the application amount of base fertilizer accounts for about 75% of the annual fertilization amount, mainly organic fertilizer and a small amount of chemical fertilizer. In the actual production management, taking the production of 1kg fruit as the standard, about 4000kg of organic fertilizer, 80 kg of phosphate fertilizer and 200 kg of plant ash were applied to pear trees in the full fruit period. Fertilization method: the base fertilizer can be applied in annular ditch or radial ditch, and the depth of ditch is about 40 cm. 2. Surface treatment

Topdressing of pear trees can be divided into rhizosphere topdressing and root topdressing.

(1) Top dressing in rhizosphere

Fertilization time and type: Top dressing in pear rhizosphere is usually carried out three times a year at full fruit stage. The first time, before germination in spring, it is also called pre-bud fertilizer. Nitrogen fertilizer is mainly used to promote the growth and development of branches, leaves and flowers, and to make preliminary preparations for improving fruit setting rate. The second fertilization before flower bud differentiation and fruit expansion period, mainly phosphorus and potassium fertilizer, promoted flower bud differentiation, reduced physiological fruit drop and was also beneficial to pear fruit expansion; The third fertilization in the later stage of fruit growth is mainly potassium fertilizer, which can be combined with nitrogen and phosphorus fertilizer, which is beneficial to fruit coloring and strengthening the stress resistance of trees.

Fertilization amount: In pear orchards with moderate soil fertility, the total amount of nitrogen, phosphorus and potassium per mu is 20 kg of urea, 20 kg of diammonium phosphate and 25 kg of potassium sulfate respectively. Fertilize 50% nitrogen in autumn, accounting for 20%, 20% and10% of the above three topdressing respectively; Apply phosphate fertilizer at one time when applying base fertilizer in autumn; Potassium fertilizer was applied in the last two topdressing, and the dosage was 60% and 40% respectively.

(2) Topdressing outside the roots

Foliar topdressing can quickly replenish nutrients for pear trees.

Top dressing time outside the root: The purpose of top dressing outside the root is to make up for the deficiency. For pear trees with poor tree potential, nitrogen fertilizer can be sprayed throughout the growth period, mainly phosphorus fertilizer, potassium fertilizer and calcium fertilizer at flowering and fruit setting stage; Spraying medium and trace element fertilizer when element deficiency disease appears.

In addition, spraying 0. 1%~0.3% mixed solution of boric acid and gibberellin at the full flowering stage of pear trees can effectively improve the fruit setting rate; Spraying the mixed solution of 0.3% potassium dihydrogen phosphate and urea at the fruit expansion stage has obvious yield-increasing effect; Pear lobular disease is a high incidence, which can be controlled by spraying 0.4% zinc sulfate and lime in May and June. When yellow leaves appear for the first time, spraying 0.3% ferrous sulfate has a good control effect.

4. Can ammonium nitrate be used as topdressing?

Ammonium nitrate can be used completely when topdressing. The nitrogen in ammonium nitrate is nitrate nitrogen, which is absorbed by pear trees faster than urea, but the price of ammonium nitrate is generally higher than urea. Therefore, if the symptoms of nitrogen deficiency are not obvious, it is suggested to choose urea from the economic point of view.

The above is the answer to pear tree fertilization. How to apply fertilizer in pear cultivation? Welcome to leave a message in the comments section.