Abstract:
Tomato (Lycoperscicum lycopersicum) production in Ghana is characterised by low yields and high fertiliser input.
This is compounded in the long run by production shocks due to environmental pressures such as drought, pests and
diseases. Tomatoes among other vegetables are more susceptible to these biotic constraints than other crops.
Chemical pesticides and, to a limited extent, integrated pest management practices have been applied to control the
pests and diseases but with limited success. Pesticides use has been ineffective, leading farmers to apply high
dosages. The aim of this study was to identify the most important sources of greenhouse gases, acidifying and
eutrophying compounds associated with tomato production in Ghana and identify options to reduce the environmental impacts. Life Cycle Analysis (LCA) methodology was used in the analysis (Cradle to gate approach). The
inventory analysis involved collection of data on raw material, energy consumption and emissions. From the results,
it was revealed that approximately 8,544 kg CO2-equivalents of greenhouse gas was emitted per hectare of tomato
production in Ghana. Among the three main components of greenhouse gases, CO2, CH4 and N2O, N2O accounted
for the highest value followed by CO2. When we considered the activities that generated greenhouse gases, fertiliser
application ranks the first with a share of 97%. The total hectare acidifying emissions from SO2 and NOX were
calculated to be 19.50 kg SO2 –equivalent. When we considered the result in terms of actual and SO2 equivalent,
emission of NO
X was larger than that of SO2. About 211.50 kg PO4 equivalent of eutrophying compounds was
found to be discharged per hectares. With regards to options to reduce environmental impact of tomato production
in Ghana, practices that recover investment cost and generate a profit in the short term are preferred over practices
that require a long term to recover investment costs: practices that have a high probability associated with expected
profits are desired over practices that have less certainty about their returns
