Key Points of Planting and Management Techniques for Fast-Growing Poplar

AbstractVariety selection: Excellent varieties with fast growth, high survival rate, good quality and strong stress resistance should be selected. Afforestation techniques: From mid-March to early April, select loose and fertile plots, and use seedlings with a 20 cm long complete root system for afforestation. Management: During the management process, work such as earthing up, watering, fertilizing and pruning needs to be done well.

I. Variety Selection

Excellent varieties with wide adaptability, fast growth, high survival rate, good quality and strong stress resistance should be selected.

II. Afforestation Techniques

1. Plot selection

Because of the characteristics of fast-growing poplar, namely fast growth and high water and fertilizer demand, fertile and loose plots with good fertility and high moisture should be selected for planting.

2. Careful land preparation

Between the harvested stumps, careful land preparation and soil maturation to improve soil fertility play an important role in restoring root growth and promoting rapid growth and high yield of the trees.

3. Land preparation method

Dig a planting hole 60 cm in length, width and height for land preparation and planting, and apply 0.5 kg of phosphate fertilizer and 10 kg of farmyard manure evenly in the hole.

4. Afforestation method

Before planting, backfill soil to half the depth of the tree pit, tread it firm and water thoroughly to the bottom, and after the water seeps in, keep the soil surface moist and place the fast-growing poplar into the hole, then fill the soil level with the ground, lift the seedling upward to spread the root system, then tread the filled soil firm and water thoroughly; the planting depth should be 10-20 cm lower than the original depth.

5. Seedling selection

It is best to use first-grade large seedlings 20 cm long with a complete root system of fast-growing poplar, planting them as soon as they are lifted; for seedlings with a long transport distance and long time, soak the root system in water for 2-3 days to absorb water, and take good root protection measures to prevent root dehydration.

6. Afforestation time

Spring from mid-March to early April, autumn from mid-October to early November.

7. Afforestation density

The afforestation density should be determined according to site conditions, tending measures, mixed planting methods, management purposes, and the growth and development stage of the fast-growing poplar, with the usual standard being 3 m×4 m or 2 m×6 m.

III. Management Techniques

1. Earthing up and watering

Earthing up: After planting, water thoroughly; for fast-growing poplars planted shallowly, with unstable trunks, or of large size, earthing up should be carried out promptly.

Watering: Test water quality before watering; never use polluted water or water with a salt content exceeding 3‰; determine the number of times according to conditions, preferably at least 4 times/year.

(1) Water in mid-March to promote sprouting.

(2) Water in early May to promote branch and leaf growth.

(3) In late June, when the temperature exceeds 24-26°C, the watering amount can be appropriately increased.

(4) Water in early November to promote root development and overwintering.

2. Fertilization

(1) Fertilization period

After leaf fall or in the following early spring is the base fertilizer period for fast-growing poplar; topdressing is done 2 times/year during the peak growth period, applying nitrogen fertilizer or compound fertilizer from late April to late May and from early June to late August.

(2) Fertilization amount

The fertilization amount should be determined according to fertilizer properties, soil type and tree vigor; for mature trees, apply 10-20 kg/tree as base fertilizer; 0.1-0.3 kg/tree urea as topdressing; 0.2-0.6 kg/tree ammonium bicarbonate; 0.2-0.5 kg/tree diammonium phosphate.

Different growth periods have different fertilizer requirements, so it can be applied in stages or at one time; for 1-3 year old young fast-growing poplars, the amount can be reduced.

(2) Fertilization method

Use furrow application or ring-shaped fertilization, dig a 30-40 cm deep ditch, backfill soil after fertilization, build a tree basin and irrigate, which is conducive to other field operations.

3. Tree management

(1) Pruning position

In the spring and autumn seasons 1-2 years after planting, prune reasonably according to tree growth conditions, which can promote a straight and full main trunk of the fast-growing poplar; generally, prune diseased and insect-damaged branches and competing branches.

In particular, for two central leaders and particularly vigorous branches, only one central leader needs to be retained; in special cases, pruning should also be done in summer to promote crown formation; after 3 years, prune to 1/3 of the height of the fast-growing poplar, and promptly prune new branches sprouting from the lower main trunk.

(2) Pruning time

The best pruning time is from late October to early November after leaf fall in late autumn, or from late February to early March before sprouting in the following spring.

(5) Pruning techniques

When pruning, keep close to the trunk and use sharp tools to prune from bottom to top; the pruning cut should be smooth, and avoid leaving stubs or tearing the bark, which is not conducive to the growth and development of fast-growing poplar.

4. Woodland management

For three consecutive years after planting, loosen the soil, remove weeds, and control diseases and insect pests, etc., to tend the fast-growing poplar.