Abstract:
Agriculture contributes significantly to the global greenhouse gas (GHG) emissions. Farmers need to fine-tune agricultural
practices to balance the trade-offs between increasing productivity in order to feed a growing population and lowering
GHG emissions to mitigate climate change and its impact on agriculture. We conducted a survey on the major cultural
practices in four potato production systems in Zimbabwe, namely large-scale commercial, communal area, A1 and A2
resettlement production systems. The resettlement production systems were formed from the radical Fast Track Land
Reform Programme initiated in 2000, which changed the landscape of commercial agriculture in Zimbabwe. We used
survey data as an input into the ‘Cool Farm Tool – Potato’ model. The model calculates the contributions of various
production operations to total GHG emission. Experienced growers were targeted. The average carbon footprint calculated
was 251 kg CO2 eq./t potato harvested, ranging from 216 kg CO2 eq./t to 286 kg CO2 eq./t in the communal area
and A2 resettlement production systems, respectively. The major drivers of the GHG emissions were fertilizer production
and soil-related field emissions, which together accounted for on average 56% of the total emissions across all
production systems. Although mitigation options were not assessed, the model outputs the factors/farm operations and
their respective emission estimates allowing growers to choose the inputs and operations to reduce their carbon
footprint. Opportunities for benchmarking as an incentive to improve performance exist given the large variation in GHG
emission between individual growers.
