The climate gradually warmed, and everything began to recover. Citrus and other evergreen fruit trees have also begun to enter the budding period and are also preparing for the flowering period.

One. The fertilization principle of citrus

The purpose of citrus fertilization is to adjust the nutritional balance, so that the vegetative growth and flowering and fruit are coordinated, not only to cultivate a strong tree vigor, but also to achieve the purpose of high quality and high yield. Are the fertilization of saplings and fruiting trees consistent?

1. Fertilize young trees

It is mainly to promote the rapid growth of branches, cultivate solid branches and good skeletons, expand the crown, and lay the foundation for early fruiting and high yield. Fertilization of young trees is mainly based on nitrogen fertilizer, supplemented by phosphorus and potassium fertilizer.

We focus on fertilizing at the time of drawing new shoots. May and June promote the growth of summer shoots, and July and August will promote the growth of autumn shoots. These two periods are the key fertilization periods. The roots of young trees have weak absorption capacity, small and shallow distribution, and no burden of fruit. Therefore, the amount of fertilizer applied at one time should not be too much, but the number of times of fertilizer application should be more (applied diligently).

2. Fertilizing the fruiting tree

After the citrus enters the fruiting period, the main purpose of cultivation is to continuously expand the canopy, while also obtaining high-quality and high-yield fruits. At this time, fertilization is mainly to adjust the balance of vegetative growth and reproductive growth, so it is necessary to fertilize scientifically and reasonably. It is necessary to ensure sufficient fertilizer and water for several periods, such as fertilizer for flowering period, fertilizer for stabilizing fruit, fertilizer for strengthening fruit, and fertilizer for picking fruit.

Flowering fertilizer is generally from late February to early March, that is, the season of horror. The amount of fertilizer applied at this time accounts for about 30% of the whole year, and it is also the most important fertilizer period. Flowering period is an important period for the growth and development of citrus, which requires both flowering and spring shoots.

The quality of the flower affects the output of that year, and the quality of the spring shoots affects both the output of the current year and the output of the next year. Therefore, at this time, water-soluble fertilizer must be used as the main ingredient, combined with organic fertilizer, to ensure good flower quality and good spring shoot quality.

The fruit stabilization period is the period of citrus physiological fruit dropping and the period of summer shoots. At this time, the main purpose of fertilization is to increase the fruit setting rate and control the sudden emergence of summer shoots. In order to preserve fruit, use foliar sprays potassium dihydrogen phosphate + amino acid foliar fertilizer, spray once every half a month, 2-3 times.

During this period, the fruit of strong fruit and fat citrus is constantly expanding, and the output of that year is basically determined. The strong fruit period is also another key period of citrus fertilization. In order to have large fruit, good autumn shoot quality, and good flower bud differentiation, high-potassium water-soluble fertilizer + balanced water-soluble fertilizer must be used in combination. The time is generally from July to August, accounting for about 35% of the annual fertilizer application.

The fruit-harvesting period of fruit-picking citrus is very long, usually from June to December. During this period, it consumes a lot of water and nutrients, and the tree is weak. The main purpose of fruit-picking fertilizer is to restore the tree vigor, continue to promote the differentiation of flower buds, enrich the fruiting mother branches, and improve the cold resistance. At this time, the root activity is poor and the absorption capacity is weak, so a large amount of organic fertilizer should be applied. The time is generally from late October to mid-December, accounting for about 30% of the annual fertilization.

Two. Fertilization method

Fertilization methods play a very important role in improving fertilizer efficiency and fertilizer utilization. The wrong method of fertilization will not only waste fertilizer, but will even harm fruit trees and reduce production. The fertilization methods of citrus are mainly divided into soil fertilization and foliar spraying.

1. Soil fertilization

Citrus is a deep-rooted plant. The roots are mainly distributed at a depth of about 60 cm in the soil, and more roots are distributed at a depth of 15-40 cm. When fertilizing, dig trenches directly between fruit trees and fruit trees to fertilize, the base fertilizer should be deep (30-40 cm), and the top dressing should be shallow (10-20 cm).

Fertilizer configuration is mainly mixed application of organic fertilizer and chemical fertilizer. A large amount of organic fertilizer is used as base fertilizer to improve soil characteristics, increase soil fertility, improve soil deep structure, and facilitate root growth; chemical fertilizer is used as additional fertilizer to provide nutrients needed by plants in a timely manner. Ensure the normal growth and development of citrus.

2. Foliar spray fertilizer

The amount of topdressing fertilizer is small, the nutrient absorption is fast, the transportation distance is short, the utilization rate is high, and the effect is quick. Generally, it can be absorbed and utilized within 1-2 hours after spraying. Foliar topdressing can reduce the waste caused by the fixation of the fertilizer by the soil, but it cannot replace soil fertilization, so citrus fertilization is mainly based on soil fertilization, and foliar fertilization is supplemented.