Rapid vegetation/plantation is needed in mines to increase green cover (Figure 1) which reduces CO2 emissions and suppresses dust generation. However, it is difficult to achieve adequate green cover in mines due to the following constraints:
- Requirement of planting at unstable dump slopes (with a slope angle of ~28o) comprising of overburden rocky material. (Figure 1)
- Unable to provide adequate water during dry seasons.
- Unable to sustain the topsoil fertility. A homogeneous top layer is not available for plantations due to the presence of boulders and rocks. (Figure 2)
- Unable to control unwanted alien invasive weeds.
Several attempts have been made over the years, which have improved the green cover to an extent:
- Drip irrigation system for effective plantation resulting in economical use of water
- Use of fertile topsoil in dumps to enhance plant growth
- Use of coir matting for dump stability, strengthening plant growth
- Plantation of Vetiver grass on graduated terraces built into the slope, enhancing the aesthetics of the dumps.
However, 10% of the new plantations wash off every year during the rainy season (Figure 3). Also, the survival rate of the remaining plants is around 75%.
Thus, we are seeking solutions to achieve a rapid growth rate of plantations in the mines. The proposed solution should help us achieve the following:
- Meeting the yearly green cover (plantation) target as per the Mining plan set forward by the Indian Bureau of Mines.
- Ensuring the plants live and grow on the surface till it attains stability.
- Ensuring maximum use of native trees for sustaining topsoil fertility. This is important from the point of restoration of biodiversity as other invasive species affect the ecosystem.
- Meet the expectations of the legal guidelines and safety aspects of the dumps.