Quality of potatoes grown in soils amended with sewage sludge

The effect of metal contaminated municipal sewage sludge on total nitrogen, nonprotein nitrogen, protein nitrogen, protein content, ascorbic acid, total phenols and enzymatic discoloration of potatoes was studied for 2 years. The cortex tissue of potatoes grown on sludge amended soils was higher in total nitrogen and protein nitrogen than controls whilst the pith tissue had lower levels. In the second year of study, both cortex and pith tissue of potatoes grown on sludge amended soil had lower ascorbic acid contents than controls. There were no noticeable differences in the other constituents measured.