Methodology to Examine Adaptations to Climate Change
Several approaches were followed to examine what farmers are already doing, and what agronomic practices might be useful to reduce the negative effects of climate change. Focus group and key informant interviews were conducted in multiple sites in Kenya, Tanzania and Uganda to to identify the impact of climate change and variability on the communities, how the impacts affect men and women, and households of different wealth categories differently, and lastly how people were adapting or coping with the changes. Crop modeling was also conducted to identify the potential benefits of nitrogen fertilizer and drought resistant maize variety to reduce the effects of climate change (only the fertilizer results illustrated here).
This section will first present results from the crop modeling, and then results from the community fieldwork.
Crop Modeling Results
The basic questions being examined are, “Is fertilizer an effective adaptive strategy for coping with climate change? Where and where not?” To answer these questions, we conducted sensitivity experiments to see how maize productivity would be affected by management practices under current and projected climate conditions (Alagarswamy et al. 2013). Two of the adaptation practices we considered are 1) short-season or drought-resistant maize varieties, and 2) better management practices, especially fertilizer application, to reduce the plant’s susceptibility (the so-called no regrets option; this is what is illustrated here).
We modeled maize under three nitrogen fertilizer application rates (a low rate of 5 kg/ha which reflects many small-holders’ practices, a moderate level of 35 kg/ha, and a higher level of 85 kg/ha) for each of the climate scenarios.
Figure 8 compares maize yield using three fertilizer levels under rain-fed, current climate conditions. The yield increases are large with relatively modest additional fertilizer across the region except in semi-arid and arid regions (e.g., northern Kenya). This result would point towards fertilizer potentially being a strong “no regrets” option for climate change.
We then tested the potential effectiveness of fertilizer as an adaptation strategy by comparing the change in yields of the low (Figure 9) and moderate (Figure 10) fertilizer levels under projected climate change. The results are that projected climate change would lead to larger yield losses with moderate fertilizer than for low fertilizer levels (i.e., Figure 10 shows higher losses, more red, than Figure 9). This is the case across most of the region, especially in Uganda and Tanzania.