Climate change is not a new phenomenon. What is alarming, however, is the scientific proof linking the current changes in global climate to man’s activities over the past century.
As weather swings from extreme dry conditions of drought to floods, farmers have to find ways of adapting to these changes.
Whereas the focus on climate change in relation to food security has mostly been around getting drought resistant crops and making water available for agriculture, devastation of crops by floods is forcing farmers to rethink this strategy. How can the farming community in developing countries ensure food security in the face of floods? Is it possible to have flood-resistant crop varieties? How can farmers take advantage of floods?
Flooding may result from excessive rainfall or when the volume of water within a body of water, such as a river or lake overflows, invading the neighbouring land.
Whatever the cause, flooding makes it difficult for plants to grow and causes tremendous damage to buildings and other property.
Although most plants during their normal cycle can withstand a couple of days of flooding, a week or more can severely affect the crops.
Symptoms of plants under excessive water stress include yellowing or browning of leaves, leaf curling and wilting, branch dieback and, in extreme cases, total plant destruction.
The plants get affected because excessive moisture causes oxygen levels in the soil to decrease, suffocating the roots. As a result, carbon dioxide, methane, hydrogen and nitrogen gas levels around the roots increase sharply, affecting the tissues. This explains why food crops like cassava cannot survive.
The eastern and north eastern parts of Uganda are becoming more prone to flooding due to excessive rains resulting from a change in the local climate.
How can farmers cope?
The obvious coping mechanism is to avoid planting in areas that drain slowly after rain and those that get flooded consistently after every heavy downpour.
Farmers can also improve drainages on the farm by creating drainage channels. Addition of loose organic material such as composted leaves or manure can improve porosity, making it easy for the soil to drain.
Farmers can also plant on raised beds and in areas where drainage cannot be improved and plant species that can tolerate floods such as plants that grow naturally in lowland areas such as yams, submergence tolerant rice and eucalyptus.
It is important to recognise the fact that different plants tolerate different degrees of wetness and farmers should follow flood patterns closely to know which crop is best suited when planting in floodprone areas.
Farmers, for example, have to know how much flood water to expect and for how long. Roots need oxygen for growth and respiration. So the longer the roots stay submerged, the more difficult it is for the plant to survive.
Extreme conditions of weather such as frequent floods are here to stay and to survive this change, African farmers have to come up with innovations. These may be in form of new crop varieties, new timing of crop seasons, for example, conserving flood water and planting in the dry season or resorting to new flood ‘compatible’ businesses such as fish farming.
Since agriculture employs the majority and still constitutes a large fraction of the GDP in developing countries, losses, however small, through flooding, have devastating effects on livelihoods. All stakeholders on food security must take action now.