Benedicta Y. Fosu-Mensah

Farmers’ perception and adaptation to climate change: a case study of Sekyedumase district in Ghana

Climate change is projected to have serious environmental, economic, and social impacts on Ghana, particularly on rural farmers whose livelihoods depend largely on rainfall. The extent of these impacts depends largely on awareness and the level of adaptation in response to climate change. This study examines the perception of farmers in Sekyedumase district of Ashanti region of Ghana on climate change and analyzes farmers’ adaptation responses to climate change. A hundred and eighty farming households were interviewed in February and October 2009. Results showed that about 92% of the respondents perceived increases in temperature, while 87% perceived decrease in precipitation over the years. The major adaptation strategies identified included crop diversification, planting of short season varieties, change in crops species, and a shift in planting date, among others. Results of logit regression analysis indicated that the access to extension services, credit, soil fertility, and land tenure are the four most important factors that influence farmers’ perception and adaptation. The main barriers included lack of information on adaptation strategies, poverty, and lack of information about weather. Even though the communities are highly aware of climate issues, only 44.4% of farmers have adjusted their farming practices to reduce the impacts of increasing temperature and 40.6% to decreasing precipitation, giving lack of funds as the main barrier to implementing adaptation measure. Implications for policymaking will be to make credit facilities more flexible, to invest in training more extension officers and more education on climate change and adaptation strategies.

The Response of Maize to N Fertilization in a Sub-humid Region of Ghana: Understanding the Processes Using a Crop Simulation Model

Crop simulation models afford the opportunity to study and understand underlying processes that impact on crop yield, hence, helps in designing appropriate strategies to improve crop production. The response of maize to N fertilization in a sub-humid environment was evaluated using DSSAT (crop simulation model). Two field experiments were conducted in the major and minor seasons in 2007. One was conducted under limited water and nutrient stress conditions and data collected used to calibrate model. The second independent experiments were conducted with different levels (0, 40, 80 and 120 kg N ha–1) of N fertilizer. Grain and biomass yields were predicted with an index of agreement of between 0.64 and 0.95 in both major and minor seasons. Biomass N content and crop phenology were also adequately simulated. Model simulations were better with higher rates of N fertilization and lesser water stress conditions. Water stress during the reproductive stage significantly affected grain yield. Sensitivity of selected soil parameters to grain yield indicated more sensitivity when no N fertilizer was applied. The DSSAT model has been satisfactorily calibrated and evaluated for the study area and hence, can be used to aid decision making in respect of farm management options.

Heavy Metal Contamination of Soils around a Hospital Waste Incinerator Bottom Ash Dumps Site

Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries. However, the release of dioxins, POPs, and heavy metals in fly and bottom ash poses environmental and public health concerns. To determine heavy metal (Hg, Pb, Cd, Cr, and Ag) in levels in incinerator bottom ash and soils 100 m around the incinerator bottom ash dump site, ash samples and surrounding soil samples were collected at 20 m, 40 m, 60 m, 80 m, 100 m, and 1,200 m from incinerator. These were analyzed using the absorption spectrophotometer method. The geoaccumulation (I geo) and pollution load indices (PLI) were used to assess the level of heavy metal contamination of surrounding soils. The study revealed high concentrations in mg/kg for, Zn (16417.69), Pb (143.80), Cr (99.30), and Cd (7.54) in bottom ash and these were above allowable limits for disposal in landfill. The study also found soils within 60 m radius of the incinerator to be polluted with the metals. It is recommended that health care waste managers be educated on the implication of improper management of incinerator bottom ash and regulators monitor hospital waste incinerator sites.

Heavy metals concentration and distribution in soils and vegetation at Korle Lagoon area in Accra, Ghana

Abstract The call for reclamation of land around Korle Lagoon in Accra, Ghana, where burning of e-waste and cultivation of vegetables takes place, makes risk assessment of heavy metal contaminations important. This study aimed at evaluating the levels and risk of heavy metal contamination in soils and vegetation around the Korle lagoon area in Accra. Geoaccumulation index, enrichment factor and pollution load index were determined to assess the risk of contamination. The levels and distribution of nine heavy metals (Pb, Hg, Cd, As, Zn, Sn, Ni, Cu and Cr) in soil (0–20 cm) and common vegetation (Panicum maximum, Imperata cylindrica, Lactuca sativa and Hibiscus sabdariffa) from the area using Atomic Absorption Spectrometer (AAS) were assessed. The area was divided into five sites, namely; the e-waste site (S1), gardens area (S2), recreational area (S3), reclaimed area (S4) estuary (S5) and the control (S6) which was about 700 m away. Soil analysis showed that the concentration of Pb (184.44 mg/kg), Cd (103.66 mg/kg), Cu (202.99 mg/kg), Ni (72.00 mg/kg) and Sn (705.32 mg/kg) at S1 exceeded their WHO/FAO thresholds for agricultural soils. Concentrations of heavy metals in soils from the e-waste site were significantly different (p < 0.01) from the other sites. High accumulations of heavy metals were also observed in the plants samples collected from the study sites, with the concentrations of Cu, Pb, Ni and Cd exceeding their acceptable limits. Laws against open burning of e-waste should be enforced and animals should be restricted from grazing on the forage.