Low crop yields in Africa is not due to climate change but rather farmers failing to exploit opportunities in wetter years, says a Kenya-based scientist.

Peter Cooper, principal scientist for Eastern and Southern Africa at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in Nairobi, argues that much of African society, particularly politicians and policy-makers, wrongly blames climate change for harvest irregularities.

Africa's emphasis on adapting to climate change could be misplaced, he said, because "other drivers of change may well be responsible".

Cooper was commenting at an ICRICAT workshop on climate change in Africa held in Nairobi last month (17 September).

He said food insecurity is widespread in Sub-Saharan Africa because of low investment in rain-fed agriculture; farmers and governments regard large-scale spending on costly items such as fertilizers, which go to waste when there is no rain, as "too risky".

Although farming practices minimise economic damage during dry years, they fail to exploit opportunities during better years. "Farmers tend to over-estimate the negative impact of variable climates," he said.

Studies indicate that farmers' perception of climate change does not always tally with national meteorological data.

For example, seasonal temperatures in Kenya, Niger, Senegal and South Africa, and rainfall in Cameroon, Egypt, Ethiopia, Kenya and South Africa have not changed, Cooper pointed out.

The farmers' misperception affects crop productivity. An ICRISAT study revealed that farmers in Zimbabwe ignored recommendations to apply more nitrogen fertilizer to maize crops in case there was no rain.

Lawrance Mose, a research fellow at the Kenya Agricultural Research Institute, said fertilizer use in Kenya hasn't changed for over a decade.

Cooper believes that measures such as lowering the price of fertilizer would help farmers cope with climate variability.

Rain-fed agriculture provides 90 per cent of sub-Saharan Africa's food staples. But at its present rate of investment, the UN Food and Agriculture Organisation projects an almost fourfold increase in the annual deficit of cereals by 2025.