Eucalyptus is one of the three fast-growing tree species, with developed roots, strong absorption and large growth. Water and fertilizer supply is sufficient, with length 1 and height 1.5-5.5 meters, which can be harvested and utilized in 4-5 years. The main nutrient elements absorbed by eucalyptus are nitrogen, phosphorus, potassium, calcium, magnesium, zinc and boron. According to the research, each eucalyptus tree absorbs 36 grams of nitrogen, 2.8 grams of phosphorus, 20 grams of potassium, 3 1 gram of calcium and 8.5 grams of magnesium every year, and the absorption capacity is nitrogen >; The absorption rate of calcium >: potassium >: magnesium >: phosphorus, nitrogen, phosphorus and potassium is: 13: 1: 8. Nitrogen-deficient plants turn green or purple, and their growth is hindered; Potassium-deficient plants are weak, prone to lodging and dull leaves; Calcium and magnesium can increase the stress resistance of eucalyptus, make eucalyptus grow rapidly, make the tree shape straight and symmetrical, and have high yield; Zinc and boron promote the top growth of eucalyptus. Without these two elements, the terminal buds of eucalyptus will dry up or the tender buds will swell and become brittle, which will be easily broken by the wind and form weak branches, which will seriously affect the growth of eucalyptus.

Second, fertilization technology

Eucalyptus fertilization should first meet the needs of eucalyptus for various nutrients; Secondly, it is necessary to achieve the right amount, with the least fertilizer input, to achieve the greatest economic benefits; Thirdly, it is necessary to master fertilization methods and improve fertilizer utilization rate.

Eucalyptus fertilization is carried out according to the following methods:

Base fertilizer: 7 days before planting, apply 0.25-0.5 kg of compound fertilizer or eucalyptus fertilizer to each hole, apply fertilizer to the hole, and backfill a layer of topsoil with a thickness of 1-2 cm.

Top dressing: after planting 1 month or young trees grow to 1 meter high, top dressing is started, and 0.25 kg eucalyptus compound fertilizer or special fertilizer is applied to each plant to promote the early growth and rapid development of eucalyptus; Topdressing once in March and April of the following year, with 0.5 kg of compound fertilizer or special fertilizer for eucalyptus applied to each plant; Top dressing once in the third and fourth years, applying 0.8kg compound fertilizer or special fertilizer for eucalyptus to each plant, eucalyptus can be cut down in 4-5 years, and the wood yield per mu can reach 6-8m3.

Top dressing points:

1, before each topdressing, be sure to weed to avoid weeds competing for fertilizer.

2, 30 cm away from the root, in the uphill direction of the root, open a crescent-shaped fertilization ditch or open fertilization holes at the top, left and right sides of the root, and cover the soil after application to prevent fertilizer loss.

3, it is best to choose fertilization after rain, fertilizer is easy to be absorbed.

4. On sloping fields and ridges, the soil is thin and thin, so more fertilization is needed. Along the gullies and valleys, the soil is thick and fertile, so fertilization should be less, and the dosage should be used rationally according to local conditions to save costs and improve efficiency.

5, soil testing and fertilization, according to the technical department to soil testing and fertilization advice card, fertilization, saving money and increasing efficiency.