Effects of Coke on Soil and Seedling Growth of different Vigna species (Fabaceae)

Coke production is one of the important source of pollution from steel industries. This paper describes the effects of coke treatment on soil and seedling growth performance of three different Vigna species viz. Vigna radiata, Vigna mungo and Vigna unguiculata. A statistically significant p<0.05 effects of coke treatment at 20% affected seedling and root length V. radiata as compared to control. The coke treatment gradually decreased root, seedling length, leaf area, leaf dry weight, root dry weight, specific leaf area and leaf area ratio of V. mungo as compared to control. The treatment of coke at higher concentration significantly (p<0.05) decreased shoot length, shoot, total seedling dry weight, root / shoot ratio and leaf weight ratio as compared to control. The coke treatment at 20, 60 and 80% had a stimulating effect on root length of V. unguiculata as compared to control. An increase in coke concentration treatment at 20-80% significantly (p<0.05) decreased leaf and root dry weight of V. unguiculata as compared to control. The seedling tolerance index for V. unguiculata (111.71%), V. radiata (105.35%) and V. mungo (80.36%) with the increase in concentration of coke at 80% was recorded. A pronounced variation in garden and coke treated soil characteristics was recorded. Soil pH was significantly (p<0.05) increased in coke treated soil (9.82, 9.79, 9.72 and 9.69). Electrical conductivity significantly increased in 80%. Water content significantly increases in 20% (11.56%) as compared to control (0.39). Bulk density showed significant decline towards higher concentration. Water holding capacity significantly increased from 40 to 80% (36.42%), (39.48%) and (47.30%) as compared to control (26.96%). Organic matter and chloride significantly increased from 20% to 80% coke treated soil. Calcium carbonate significantly reduced in 80% coke treated soil. Exchangeable potassium and sodium showed no significant differences among treatment.