IMPACT OF LONG-TERM MUNICIPAL SOLID WASTE ON SOIL PHYSICOCHEMICAL PROPERTIES IN NSUKKA, SOUTHEAST NIGERIA

This study was carried out to assess the impact of long-term (above 10 years) municipal waste disposal sites on soil physicochemical characteristics and also on heavy metal concentration on the surface (0-20cm) and sub-surface (20-40cm) depths of the dump sites comparing them with those from non-dump sites within the study locations. The research was conducted at Edem Nru, Owerre-Eze Orba and Obukpa, all less than two kilometres from the University of Nigeria, Nsukka. Twenty-four (24) cylindrical core and auger soil samples were collected at the same depth intervals in the dump and non-dump sites of the three locations. The results obtained showed that among the particle sizes, clay content at 20-40 cm depth was significantly (p<0.05) higher at the non-dump site than at the dump site, saturated hydraulic conductivity at 0-20 cm depth was significantly (p<0.05) higher at non-dump site than at the dump site, bulk density at 0-20 cm depth was significantly (p<0.05) lower at the dump site than at non-dump site but at 20-40 cm depth it was the reverse, total porosity at 0-20 cm depth was less at dump site than at non-dump site but at 20-40 cm depth it was the reversed. At the surface (0-20cm) depth; soil pH, available phosphorus and cation exchange capacity were significantly (p<0.05) higher at dump sites but total N was lower while at the sub-surface (20-40cm) depth; organic carbon, exchangeable acidity, cation exchange capacity, exchangeable calcium and magnesium were significantly (p<0.05) higher at the dump sites. Only Pb and Zn contents were significantly (p<0.05) higher at the dump sites and at 0-20 cm depth. Thus, long term dumping of municipal solid wastes appeared to have influenced soil chemical properties positively in the areas and may improve the agricultural productivity of the soils