摘要
Disposal of domestic and industrial waste into the Odaw River and Korle Lagoon in Accra, Ghana, has led to pollution of the lagoon and surrounding soils. This study compared the elemental concentrations of heavy metals (lead and zinc) and essential plant macronutrients (nitrogen, phosphorus and potassium) in soils from the Korle Lagoon Area to those in baseline soils from the University of Ghana Agricultural Farm (UG Farm), also in Accra. A comparative pot experiment, using maize (Zea mays L.) as test plant, was conducted to assess the effect of each soil type on plant growth. Soil samples from the Korle Lagoon Area were significantly higher (P < 0.001) in lead (Pb), zinc (Zn), nitrogen (N) and potassium (K) concentrations than samples from the UG Farm. Mean plant height and mean leaf width of maize plants harvested 7 weeks after planting (WAP) were both significantly higher (P < 0.003) for samples from the Korle Lagoon Area soil compared to those from the UG Farm soil. Higher accumulation of Zn (448.3 ± 45.5) in maize shoot within 3 weeks of planting in the Korle Lagoon Area soil had phytotoxic effects on growth, resulting in shoot growth inhibition and reduced uptake of P and K in 11-week-old plants. The findings indicate that though nutrient enrichment due to sewage disposal into the lagoon may increase crop production, the nutritional quality of the crop produced could be compromised by heavy metal accumulation in the soil and subsequent uptake by the plant.
Disposal of domestic and industrial waste into the Odaw River and Korle Lagoon in Accra, Ghana, has led to pollution of the lagoon and surrounding soils. This study compared the elemental concentrations of heavy metals (lead and zinc) and essential plant macronutrients (nitrogen, phosphorus and potassium) in soils from the Korle Lagoon Area to those in baseline soils from the University of Ghana Agricultural Farm (UG Farm), also in Accra. A comparative pot experiment, using maize (Zea mays L.) as test plant, was conducted to assess the effect of each soil type on plant growth. Soil samples from the Korle Lagoon Area were significantly higher (P < 0.001) in lead (Pb), zinc (Zn), nitrogen (N) and potassium (K) concentrations than samples from the UG Farm. Mean plant height and mean leaf width of maize plants harvested 7 weeks after planting (WAP) were both significantly higher (P < 0.003) for samples from the Korle Lagoon Area soil compared to those from the UG Farm soil. Higher accumulation of Zn (448.3 ± 45.5) in maize shoot within 3 weeks of planting in the Korle Lagoon Area soil had phytotoxic effects on growth, resulting in shoot growth inhibition and reduced uptake of P and K in 11-week-old plants. The findings indicate that though nutrient enrichment due to sewage disposal into the lagoon may increase crop production, the nutritional quality of the crop produced could be compromised by heavy metal accumulation in the soil and subsequent uptake by the plant.
作者
Eureka Emefa Ahadjie Adomako
Dzifa Dellor
Eureka Emefa Ahadjie Adomako;Dzifa Dellor(Department of Plant and Environmental Biology, University of Ghana, Legon, Accra, Ghana;Department of Internal Medicine, University of Ghana Medical Centre, Legon, Accra, Ghana)
