Effect of grass species root for enhanced slope protection in amended coalmine overburden dump soil

Background and aims Surface protection of coalmine overburden (OB) dumps against shallow slope failures can be achieved through a cost-effective and sustainable solution, i.e., vegetative cover. Hence, a small-scale study is needed to study the survival, growth performance, and root distribution of plants prior to conducting a pilot-scale study. Methods In the present study, three plant species, Dendrocalamus strictus (Bamboo grass), Cymbopogon citratus (Lemon grass), and Chrysopogon zizanioides (Vetiver grass), an endemic grass species, are studied for the slope stabilization potential of OB dumps in Jharkhand, India. Growth characteristics and root architecture of grasses grown for five months under six varying proportions (treatments) of overburden, cow dung, and garden soil were studied. Results It was found that Vetiver grass had the highest root area ratio, followed by Bamboo grass and Lemon grass. The maximum root cohesion was found to be 1 kPa for Bamboo grass, 7.33 kPa for Lemon grass, and 9.24 kPa for Vetiver grass among different treatments. Conclusions Treatment condition with 80% overburden and 20% cow dung was suggested to be the best soil mix for optimum growth of the chosen grasses, which have the potential to mitigate surficial movement of soil mass on the overburden dumps through root reinforcement.