LY/T 3180-2020Technical regulations for soil remediation of degraded forestlands in the dry and dry-hot valley regions in China (English PDF)

3.1 Degraded forestland

The sparse forest land formed due to severe disturbances such as logging and geological disasters presents difficulties in vegetation restoration and regeneration, and the soil humus layer is barren and the soil There are phenomena such as compaction, desertification, and barrenness.

4.1 Repair principle

Follow the principle of ecological restoration, give full play to the role of nitrogen-fixing broad-leaved trees in soil improvement, soil restoration, water and soil conservation, etc., and promote the restoration of degraded woodland soil and the positive succession of communities in the dry and hot valley regions can achieve the purpose of restoring the degraded soil.

4.2 Tree species selection

Priority is given to good native drought-tolerant, nitrogen-fixing broad-leaved trees or shrubs. See Appendix A for their types and suitable habitats.

4.3 Site preparation

4.3.1 Site preparation time

One month before winter or afforestation.

4.3.2 Site preparation method

4.3.2.1 Cave-like site preparation

Applicable to various tree species and site conditions. Select suitable areas for afforestation tree species, and arrange planting holes along the contours so that the hole faces are inclined inward and slope the surface is at an angle of 10°~20°, and the specifications of the planting holes vary with forest types, seedling specifications and site conditions.

4.3.2.2 Site preparation for fish scale pits

Suitable for river valleys and steep slope areas. The fish-scale pits are approximately half-moon-shaped pits, the size of which varies with forest species, seedling specifications and site conditions.

High and low, the long diameter expands along the contour, and the short diameter is slightly smaller than the long diameter.

4.3.2.3 Ditch land preparation

Suitable for land preparation for afforestation. Dig planting trenches in the planting row, dig pits for planting in the trenches at a certain pitch, and keep the trenches for a long time.

4.3.2.4 Catchment and land preparation

Suitable for flat afforestation land. Trench the ditch in a relatively flat afforestation land, turn the soil on both sides of the ditch, mound the sides of the ditch to form side slopes, and then drive in the ditch.

Horizontal ridge, a certain area of double-sided slope catchment area enclosed between two side slopes and two horizontal ridges.

4.4 Quality of seedlings and seeds

4.4.1 The quality requirements of afforestation tree species seedlings shall be implemented in accordance with GB 6000, and level I and II seedlings shall be selected. For attachments not covered in GB 6000 for the tree species in record A, choose seedlings that are robust, well-developed, free from pests and diseases, and without mechanical damage.

4.4.2 The quality requirements for direct seeding afforestation seeds shall be implemented in accordance with GB 7908, with I and II seeds selected. For attachments not covered in GB 7908 for the tree species listed in A, choose mature, full-grained, and vigorous seeds.

4.5 Seedling afforestation

4.5.1 Seedling method

4.5.1.1 For bare-rooted seedlings, the seedlings should be kept upright when planting, the planting depth should be appropriate, the roots of the seedlings should be fully extended, and it is conducive to drainage and Store water to protect moisture.

4.5.1.2 For container seedlings, hole planting is adopted, and the planting hole should be slightly larger than the container size. When planting, the containers that are not easily degradable should be removed.

4.5.2 Planting density of seedlings

See Appendix A.

4.5.3 Afforestation time

Forestation in the rainy season. Container seedlings and seedlings with soil tufts can be planted in all seasons outside of the soil freezing period.

4.5.4 Mixed forest configuration

Mixed methods such as row, block, and random configuration can be adopted, and the number of individual tree species accounts for less than 50% of the total number of afforestation.

4.5.5 Requirements for replanting

Seedling planting refers to the regulations of GB/T 15776.When the survival rate is less than 85%, replanting should be carried out.

4.6 Live afforestation

4.6.1 Germination method

The seed germination of afforestation tree species shall be implemented in accordance with LY/T 1880 and Appendix A.

4.6.2 Live broadcast method

4.6.2.1 Holecasting

A few (large seeds) to dozens (small seeds) are sown evenly into the planting hole, and then covered with soil to suppress. The thickness of the covering soil is straight for the seeds 2 to 3 times the diameter, the thick soil can be thinner, sandy soil can be thicker.

4.6.2.2 Drilling

Sow the seeds in single or double rows on the sowing belt, continuously or intermittently, and put the seeds in the soil or cover the soil to suppress them. The thickness of the covering soil should be the diameter of the seed 3 times to 5 times, clay soil can be appropriately thinner, sandy soil can be appropriately thicker.

4.6.3 Live time

rainy season.

4.7 Upbringing and management

Tending for 3 to 5 years, the first tending is carried out in September to October, and the second year and thereafter in May to June. The technical requirements are in accordance with GB/T 15781 carried out.