Better use of technologies could help African farmers counter the negative effects of a changing climate.
Using climate and crop growth models, researchers from the International Crops Research Institute for Semi-Arid Tropics (Icrisat) found that African and Asian small-holder farmers would be able to increase food production by improving fertiliser use, harvesting rain water and using mulches. Even with a 3˚C temperature increase and minimum functional rainfall levels, production could double.
“The world is locked into the inevitable changes of climate patterns and, however uncertain those changes might be, farmers must adapt to them,” says Dr William Dar, former director-general of Icrisat, now president of the InangLupa Movement that pursues urgent, collective, and cohesive action, towards poverty alleviation, food and nutrition security.
Models agree that temperatures are rising steadily in the tropics, but rainfall pattern predictions differ.
Increases in temperature reduce the growing period, defined as the number of days the soil has enough water stored to support crop growth to full maturity. High temperatures also speed up crop growth leading to earlier, premature flowering resulting in depressed yields.
Scientists say the impact of rising temperatures on yields from low-input agricultural systems, could be minimal compared to factors such as low and declining soil fertility, poor weed control and lack of water conservation practices.
Fertilisers boost yields
Adopting existing recommendations for improved crop, soil and water management, even with increased temperatures, will result in substantially higher yields than farmers are currently getting, according to Icrisat’s principal scientist Dr KPC Rao.
Most farmers in sub-Saharan Africa rely on unpredictable rainfall to produce food and generate income, and are in any case vulnerable to climate shocks and rainfall variability. Climate change will make matters worse for them.
These farmers have evolved highly risk-averse mechanisms to cope with erratic rainfall and temperature. To minimise possible losses, they invest as little as possible in farm inputs.
This kind of strategy, not uncommon in farmers in the commercial sector when things get difficult, locks the farmer into a downward spiral. Improving methods of cultivation helps to increase water retention in the soil, even under warmer climate conditions, leading to better crop growth and yields, says Rao.
“We find that vulnerable communities tend to overestimate the negative effects of climate-induced uncertainties by trying to minimise losses, but this also means they fail to take full advantage of better seasons, and lose opportunities to recoup losses from poor seasons.”
On the positive side, governments can help farmers prepare to cope better with the impacts of climate change, by promoting good management of soil fertility and water conservation.