Studies were conducted to assess if the sludge supplementation in soil induces stress in plants.
Tomato plants variety Pusa Hybrid 2 was raised in soils supplemented with sludge in different
proportions (25, 50, 75 and 100%). Measurement of morphological, physiological and biochemical
indices indicated no alteration in the growth till 50%, though an inhibition in growth was noted at
higher concentrations. The levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2) did not
show any change in comparison to control till 50% concentration. The increase in MDA and H2O2
at higher concentrations (75 and 100%) suggested the induction of oxidative stress. The
accumulation of compatible solutes was evident in plants raised in soil supplemented with high
proportions of sludge (75 and 100%). Studies suggested that sludge supplementation in soil promote
growth in plants up to a certain concentration without inducing stress.