Accumulation of metals, antioxidant activity, growth and yield attributes of mustard (Brassica juncea L.) grown on soil amendments with fly ash together with inorganic nitrogen fertilizer

The study was accompanied to assess the effect of varying levels (0, 20, 40 or 60 t ha−1) of fly ash (FA) and nitrogen (N) (0, 60 or 80 kg ha−1) on Cd, Cr and Pb accumulation, antioxidant activity and yield traits of two mustard cultivars (Brassica juncea cv. ‘Varuna’ and ‘Pusa Bold’). The results showed that antioxidant activity increased concurrently as the FA levels increases. The dose of FA60 accompanied with N60 and N80 lowers enzymatic activity, photosynthetic pigments level, and yield; however, FA at the rate of 40 t ha−1 together with N60 significantly enhanced the crop productivity followed by N80. These results suggest that FA40N60 proved optimal for enhancing crop growth and yield, whereas a high concentration of FA (FA60) caused oxidative stress in both mustard cultivars. Oleic and linoleic acid contents were increased; however, erucic acid content decreased by the application of FA40N60.