Effects of manganese waste on growth,nodulation, proline levels,and enzymatic activities in Vigna unguiculata (L.) Walp.

Phytoremediation studies were carried out on the waste of Kalakhunta manganese (Mn) mines located in Banswara, Rajasthan, which is rich in Mn and iron. Various treatments, including the addition of soil, farmyard manure, sawdust, and biogas slurry, as well as differing quantities of NPK and capping with 10% soil were undertaken to ameliorate the effects of inhospitable waste. The effect of unamended and variously treated amended waste was studied on the growth, nodulation, yield, leaf area, and enzymatic activity of the test plants to ascertain the degree of toxicosis that plants may encounter during the process of phytostabilization. The levels of proline and activities of polyphenol oxidase, peroxidase, acid phosphatase, and nitrate reductase were affected by the treatments applied. Data showed that addition of 10% soil + 3 NPK is the most suitable treatment for the purpose of revegetation of Mn-mine waste, as the plants displayed the highest growth under this treatment condition.