Variation in antioxidant potential of Vigna unguiculata grown in pure and amended soil

Abstract EN

The variation in antioxidant capacity of Vigna unguiculata was determined by carrying out a pot experiment in pure and amended soil.

The soil amendments were done with various percentages of sewage sludge, and the suitable percentage of sewage sludge in the soil was assessed for agricultural purpose.

V.

unguiculata was grown in separate pots with varying soil amendments, including control soil, 20%, 40%, 60% and 80% sewage sludge proportion in the soil and with pure sewage sludge.

The contents of grown plants were extracted by solvent extraction, and all extracted samples were subjected to analyses in order to determine the growth parameters and antioxidant capacity variations among them as a factor of soil amendments.

The antioxidant contents increased in a linear fashion in all plant parts when grown in soil amendments possessing 20%, 40% and 60% sewage sludge proportion.

However, in the cases of the plants grown in 80% sewage sludge soil amendment and in pure sewage sludge, the antioxidant contents decreased considerably.

This can be attributed to the enhanced oxidative stress caused by higher concentrations of metal ions present with in the sewage sludge.

Plants showed significant improvement in antioxidant potential assessed by a DPPH assay, ABTS+ scavenging activity and lipid peroxidation method up to soil amendments with 60% sewage sludge proportion.

On the other hand, the antioxidant ability showed a decreasing trend at higher proportions of sewage sludge in the soil.