Xiangtan Manganese Mining Wasteland Ecological Restoration Pilot Study

The mining wastelands not only occupied the massive lands but also seriously polluted the environment. Therefore, the ecological restoration of wastelands is an urgent and important research task . Based on the ecological restoration experiment in the mining wastelands, the study aims at raising theory and technology for ecological restoration in Xiangtan Manganese Mine and other similar mines. The conditions of the plants and soils were investigated. The basic physical and chemical properties of the tailing wastelands were as following: (1)a tendency to fluctuate of the bulk density in different depth; (2)sand clay: (3)the low percolation rate, the maximum hygroscopic moisture 17.48%; (4)pH 7.45, organic matter 3.277%, total N 0.079%, total P 0.035%, total K 0.144%; (5)total Mn 82199 mg/Kg, total Cd 9. 246mg/Kg, total Pb 198.36 mg/Kg, total Zn 662. 26 mg/Kg. These indicate that the tailing wastelands have poor ventilation and water permeability, water accumulation in rainy weather, water deficit in dry weather, the low content of N and K. The concentration of Mn and Cd was 175 times and 76 times higher than the background value in Hunan Province, which seriously affected plant growth. The basic physical and chemical properties in slag wastelands are as following: ゛ small tendency to fluctuate of the bulk density in different depth; (2)satidy soil with a little stone; ﹉igh percolation rate, the maximum hygroscopic moisture 8. 63%;﹑H 9. 18, organic matter 0. 726%, total N 0. 047%, total P 0.043%, total K 0. 079%;﹖otal Mn 52924 mg/Kg, totaled 4. 375mg/Kg, total Pb 354. 1mg/Kg, total Mg 4. 02%. These show that the slag wastelands have little water accumulation and high evaporative power, alkaline soil, the low content of organic matter, N, P, K. The concentration of Mn and Cd was 114 times and 33 times higher than the background value, which was an effect on growth and development of the plants. Thereafter, the factors of soil are the major obstacle for the ecological restoration in Xiangtan Manganese Mine wastelands. Based on the soil test, soil amelioration and the selection of tolerant species were applied. The paper discussed the effect on plant growth, nutrient uptaking, heavy metal injury in different treatments of mining wastelands. The result showed that the media amelioration was beneficial to the plants. The application of fertilizer not only improved plant growth, but also inhibited the uptaking of heavy metals by-plant and reduced injury. The tolerant plants in tailing wastelands included Euonymus japonicus Thunb., Magnolia grandijlora L, Trachycarpus fortunei H. Wendl, Pittosporum tobira Ait. The tolerant ones include Koelreuteria paniculata Laxm., Platycladus orientalis Franco cv. Sieboldii, Trachycarpus fortunei H. Wendl.