Can the time and method of fertilizing poplar be sprinkled on the surface

The first fertilizer was applied from the end of May to the beginning of June in the first year, with 0.05-0.1 kg urea per plant, which could be applied within 1-2 square meters of poplar root base before rain, and then applied again at the end of July, the amount and method of fertilizer application was the same as that of the first time. In the first and middle of May of the second year, each plant was applied 0.5 kg of superphosphate and 0.2 kg of urea, which could not be applied to the surface, but could be applied in an annular trench 20 cm deep near the outer edge of the crown projection.

1. Fertilization time for poplars

The main results are as follows: 1. Fertilization in the early years can not only increase the growth base of poplar, but also promote the growth of later years. The first fertilizer is applied from the end of May to the beginning of June in the first year after planting. 0.05mol-0.1kg urea per plant can be applied within 1-2 square meters of poplar root base before rain, and the second fertilization can be carried out at the end of July. The amount and method of fertilization are the same as the first.

2. Calcium superphosphate 0.5kg and urea 0.2kg can be applied to each plant in the first and middle of May of the second year, and urea 0.25kg can be applied to each plant in the first ten days of May of the third year. During this period, deep annular grooves of 20cm can be opened near the outer edge of the crown projection, or deep holes of 20cm can be dug at no less than 3-4 places on the outer edge of the crown, and then fertilizer can be applied and covered with soil immediately, and the holes should be evenly distributed in all directions.

2. Methods of fertilization for poplars

1. During afforestation, the application of base fertilizer in the planting hole has a better effect, which can supply fertilizer and improve the physical and chemical properties of the soil for a long time. The base fertilizer generally uses farm manure and slow-acting chemical fertilizer, and soil miscellaneous fertilizer, cake fertilizer and green manure can be used during the period.

2. Soil miscellaneous fertilizer can be applied 10-20kg per plant, rapeseed cake or cottonseed cake can be applied 2-5kg per plant, and green manure is applied after crushing, and each plant is 10kg. Generally, topdressing is not necessary in the year of afforestation, because the root system of seedlings is in the recovery period and the ability to absorb nutrients is relatively weak.

3. Each young tree is fertilized with 150g nitrogen, 150g phosphorus pentoxide, 25g potassium oxide and 10kg green manure of Amorpha fruticosa. Generally, the height growth of young poplar forest can reach 2-3m. Planting Amorpha fruticosa and Shadawang as green manure under the forest in the west of Shandong Province has very good economic and ecological benefits.

4. The fertilization of poplar is mainly nitrogen fertilizer. In the soil with low content of organic matter, farm manure can be used as base fertilizer, and then topdressing nitrogen and phosphorus fertilizer can obviously promote the growth of poplar. The effect of combined application of nitrogen, phosphorus or nitrogen, phosphorus and potassium is better than that of single application. Therefore, it is best to apply two or three kinds of fertilizers together, mainly nitrogen fertilizer, and determine the amount according to the soil conditions.

5. The amount of nitrogen is generally 250-500g per plant, nitrogen: phosphorus pentoxide: potassium oxide = 3 (2): 1Rom 0.5, urea commonly used contains 46% nitrogen, and calcium superphosphate contains P2O514%.

6. The application of nitrogen fertilizer, phosphate fertilizer and green manure has a very obvious promoting effect on poplar growth. The volume growth, DBH and tree height of the fertilizer application area are 274.2%, 74.5% and 69% higher than that of the control, respectively. The effect of green manure is more obvious, followed by phosphate fertilizer and nitrogen fertilizer, while the effect of potash fertilizer is not good, chemical fertilizer should be used in combination with green manure.