Determine the site of economic afforestation in waste land after coal mining in Quang Ninh

Abstract

On the basis of the characteristics of the site after the coal mining, some species of grass grow naturally on the surface of the site, and the main plantation species for the Northeast... The article has identified 5 factors It is a group of landfill sites after coal mining in Quang Ninh, including: (i) Time after discharge; (ii) percentage of land/mixed waste; (iii) slope; (iv) Relative height; and (v) vegetation indicator. Thereby, the proposed structure of major economic afforestation and auxiliary plant species according to the difficulty of the site type groups: (a) Little difficulty: Acacia hybrid, Acacia mangium Wild, Pinus merkussi J, Pinus massoniana Lamb, Bamboo thread, etc; (b) Medium difficulty: Acacia hybrid, bamboo, Pinus merkussi J, Pinus massoniana Lamb, etc; and (c) Difficulties: Pueraria montana (Lour) Merr, Impomaea mauritana Jacp, Combination of Acacia, Pongamia pinnata, Camellia sasanqua Thunb. The main silvicultural techniques applied are as follows: Planting pure or mixed in ice, planting density from 1,660 - 2,500 trees/ha, seedling standard: Dgoc = 0.5 - 0.6 cm, Hvn = 45 - 50 cm; Apply 100 – 200 g NPK/hole, combined 100 g microbial organic fertilizer and 10g humectants/hole; take care twice a year, combined NPK 100 g/tree/time