Can poplar still be fertilized after beginning of autumn

Not bad, but a little bad. Let's talk about it from several aspects.

1. When will poplar be fertilized?

Fertilization time of poplar: base fertilizer should be applied, and seedlings and trees should be fertilized.

Second, the fertilization method:

It is very effective to apply base fertilizer in planting holes during afforestation, which can provide fertilizer for a long time and improve soil physical and chemical properties. The base fertilizer is generally farmyard manure and slow-release chemical fertilizer, which can be used to compress soil miscellaneous fertilizer, cake fertilizer and green fertilizer. Soil miscellaneous fertilizer can be applied 10 ~ 20k g/ plant, cottonseed cake or rapeseed cake can be applied 2 ~ 5kg/plant, and then applied after crushing; Green manure is more than green manure, per plant 10 kg. There is no need for topdressing in the year of afforestation, because the root system of seedlings is still in recovery period and its ability to absorb nutrients is weak.

Each young tree contains nitrogen150g, phosphorus pentoxide150g, potassium oxide 25g and Amorpha fruticosa green manure10kg. At this fertilization level, the DBH growth of I-2 14 Populus euphratica forest is about 5cm, and the height growth is 2-3 m. In the western Shandong area, planting Amorpha fruticosa and Astragalus adsurgens as green manure has good economic and ecological benefits.

Poplar fertilization should be mainly based on nitrogen fertilizer, and soil with low organic matter content can obviously promote poplar growth by using farmyard manure as base fertilizer and topdressing nitrogen and phosphorus fertilizer. The effect of nitrogen, phosphorus or nitrogen, phosphorus and potassium combined application is better than that of single application. Therefore, the combination of two or three fertilizers is mainly nitrogen fertilizer. The amount and proportion of nitrogen, phosphorus and potassium are determined according to soil conditions. The dosage of nitrogen is generally 250-500g per plant, and the ratio of nitrogen: phosphorus pentoxide: potassium oxide is 3 (2): 1: 0.5. At present, most poplars only apply nitrogen fertilizer, and the tendency to ignore phosphorus fertilizer should be corrected. The author puts forward the following fertilization schemes for cultivating large-diameter timber and small-diameter timber for reference. The urea used contains 46% nitrogen, and the superphosphate contains P2O5 14%.

Applying nitrogen, phosphorus and green manure can obviously promote the growth of poplar. Compared with the control area, the volume growth, DBH and tree height in the fertilization area increased by 274.2%, 74.5% and 69% respectively. The effect of green manure is obvious, followed by phosphate fertilizer and nitrogen fertilizer, and the effect of potassium fertilizer is not obvious. Fertilizer should be combined with green manure.

Third, how many times does poplar fertilize a year?

Rational fertilization: early fertilization of poplar can increase the growth base and promote the growth in later years. The second fertilizer was applied at the end of May and the beginning of June in the second year after planting, with 0.05-0. 1 kg urea per plant. Before it rains, the second fertilization can be carried out at the end of July, with the same amount and method.

In the first half of May of the following year, 0.5 kg of calcium superphosphate and 0.2 kg of urea were applied to each plant; In the first ten days of May of the third year, 0.25 kg urea was applied to each plant. Fertilization method is to open an annular ditch with a depth of 20 cm near the protruding outer edge of the crown, or dig a hole with a depth of 20 cm at the outer edge of the crown at least 3-4 places, apply fertilizer and cover the soil immediately. The latter method should ensure that holes are evenly distributed in all directions to avoid uneven growth and cracking of poplar trunks in all directions.