The extensive use of lithium (Li) ion-based batteries has increased the contamination of soil and water systems due to widespread dispersal of Li products in the environment. In the current study, the influence of Li application on soil fertility and leachate was observed. Three soil samples were collected and five treatments of Li (0, 50, 100, 150 and 200 mg/L) were applied. After three months of Li treatment, leachate was collected and soil samples were subjected to physical and chemical analyses. The results showed that the mean values of soil pH were increased slightly after Li application while electrical conductivity (EC) ranged from 1.2 to 5.1 µS/cm, indicating that soil was slightly saline in nature. The sodium was observed to be greater than the recommended values (0.3–0.7 mg/kg) in Li-amended soil while calcium and magnesium values decreased in soils compared to untreated soil. Mean values of phosphorus and potassium were greater before Li application and reduced considerably after Li application. Leachate analysis showed that all the parameters differed significantly except those of zinc and iron. The EC of leachate samples ranged from 2286–7188 µS/cm, which shows strong salinity. The sodium adsorption ratio (SAR) ranged from 1–11, which indicates that it falls into the marginal soil category. Lithium concentration in leachate samples ranged from 0–95 mg/L, which was significantly higher than the acceptable value for lithium (2.5 mg/L) in leachate. A soil sample (3) with an additional 10% organic matter showed that after Li application, the loss of nutrients in leachate was less as compared to the other two samples, demonstrating that organic matter improved soil conditions and suppressed the negative effects of Li on soil. Our results could raise concerns about risks in situations where food and fodder crops are associated with Li-contaminated waste disposal.
Limestone quarrying is an active mining practices generating bulk of solid remains and altering the habitat by the removal of plants; however, the utilization of such waste for the growth of plants has not been investigated much. The present study aimed to evaluate the effects of limestone quarry waste on the growth of two native plants by analyzing its physicochemical properties and utility for plantation purposes, while determining whether mitigation measures would be required for the habitat restoration of quarry site. Two species,Acacia modestaandAdhatoda vasicawere selected from the quarry site habitat. These plants were grown in different proportions of quarry waste, and garden soil was used as a control. Growth was assessed by recording plant height, number of branches per plant, root and shoot length, and total biomass. We also analyzed the N, P, K, Na, Ca, and Mg contents of the root and shoot tissues of both species. We found a significant increase in plant height (1.24- and 1.19-fold greater than controls forA. modestaandA. vasica, respectively). Differences in the number branches, root, shoot length, and biomass were also found. A significant and positive relationship was found between the mineral content in roots and the total plant biomass across both species. We conclude that (1) the mining solid waste contained the necessary minerals for the studied plant species and no amelioration would be required for restoration of such sites with the selected indigenous plants; and (2) the quarry waste promoted the growth of the two selected species. The results of the present study can be used to plan habitat restoration in limestone mining areas that have lost plant cover.
The southern tip of the Thal desert in Pakistan harbors the remnants of the original tropical thorn forest, amounting to two percent, which covered the province of Punjab a hundred years ago. In the past three decades, there has been a progressive decline in woody species cover on dunes, which is directly related to the increase in population in the surrounding area. Stabilized and destabilized dunes were subjectively selected followed by quantification of cover and diversity of woody species on the top and lower slopes. Dunes closely resembling the overall cover were grouped to suggest corresponding restoration measures. The results suggest that trends of decrease in cover and diversity of woody species were evident in the upper slopes of some stabilized dunes having less than 50% cover. The destabilized dunes with less than 20% cover are highly vulnerable to erosion. A general trend observed among dunes was that with a decrease in the cover of upper slopes, there is a decrease in the cover on lower slopes. The number of destabilized dunes is increasing without effective restoration measures against the prevailing trends of disturbances. Ranking dunes on the basis of cover could help in proposing simple restoration measures as a first step towards developing an understanding of designing adaptive strategies to restore the woody cover.