While facing increased variability in South African climate, we discuss forms of adaption for farming.
It is evident that in the event of climate change, farmers will need to adapt. As evidence points towards a drier and hotter South Africa new models for farming will need to be adopted.
If rainfall patterns change and temperatures continue to change, it will have an unknown effect on the practise of agriculture. There are many variables that need to be considered such as a change of rainfall pattern which includes when rains fall and how much rain falls. A temperature increase will affect both the average and maximum temperature which could have a negative effect on crops and livestock.
A shift to a drier climate
All climate models indicate an increase in temperature in Southern Africa of between 1°C – 3°C, with the sharpest increase manifesting in already arid regions. This means that average temperatures for summer and winter will increase as well as the maximum temperatures.
This will have a strong impact on the agricultural sector as certain crops need specific temperatures to grow and develop. Director Andre Roux discusses chill units, which is a measurement of a plant’s exposure to chilling temperatures. These chill units are particularly important in the fruit industry. However, with an increase in temperature across the board the chill units, or days plants are exposed to cold temperatures, drop.
This has a negative impact on the development of a plant’s fruit. For example, Roux shares a story of table grapes that were exported to Europe which arrived rotten due to experiencing ten days of continuous high temperatures above 30°C (even at night) in January of 2016. Even though irrigation was sufficient, the consistent high temperatures resulted in a shorter shelf life of the grapes.
Climatologists predict a decrease of rainfall, but that rainfall patterns are harder to predict than temperature, says climatologist Peter Johnston. Yet, most climate models still lean towards a drier South Africa. This could spell trouble given that that the agricultural industry currently uses 60% of South Africa’s scarce water resources for irrigation. This water consumption from the agricultural industry is said to double by 2030 due increasing demand of food and water security of a growing population, as well as a drier environment due to climate change.
Adapting to a warming climate
“The thing about adaption, is that if you just say ‘adaption’ nobody knows what to adapt to, and when,” informs Peter Johnston from Climate Systems Analysis Group, Cape Town.
Johnston emphasises the importance of a strict adaptation plan in the agricultural industry. According to him, there are two ways of adaption. The first is natural adaption, whereby farmers adapt according to seasonal or annual variability, such as preparing for a dry or wet winter. Certain precautions are taken to prepare for these natural variabilities, such as reducing inputs and cutting down on livestock and crops during a drier season.
He then uses this form of natural adaption as a floor-plan to help farmers adapt to a changing climate. “You say, ‘You know those dry years in the Western Cape, the future will look more like that’,” Johnston shares. This helps farmers prepare for the kind of weather variability that will be seen more frequently in their region.
Farming for the future
A warming climate in South Africa could lead to a loss of certain crop types and the introduction of new crops. For example, crops like potatoes will shift to other agricultural zones as the climate changes, says Professor Roland Schulze from University of Kwazulu-Natal. Maize is also becoming marginal in the drylands like Free State and the North West, and farmers are looking towards the Eastern Cape for future maize farming, says climatologist Peter Johnston.
There are ways of practising farming that lessens the effects of climate change and is more sustainable for the future. Director Roux introduces the topic of ‘conservation agriculture’, defined by the UN as:
“Conservation agriculture is a concept for resource-saving agricultural crop production that strives to achieve acceptable profits together with high and sustained production levels while concurrently conserving the environment,” Food and Agricultural Organisation of the UN.
Conservation agriculture practises minimum tillage and disturbance of the land, as it can lead to destruction of soil structure. Traditional agriculture practise means ploughing the land seen to nine times before planting the seed and leaving the newly upturned soil exposed to summer temperatures as high as 70°C. The organic material in soil gets destroyed in temperatures higher than 38°C. Crop cover is also left on the fields to protect the land from erosion in harsh summer temperatures. Roux says it is also important to rotate crops to allow the land time to recover from intensive agriculture.
Roux says that conservation agriculture has remained effective even during the latest drought. In the Western Cape farmers practised minimum tillage, planted seed and prayed for rain in April. Rain did fall on time allowing for germination. But the absence of rain in August and September 2015 lead to many traditional farmers losing their crops, yet the conservation farmers managed to make a small profit.
Peter Johnston mentions other ways for farmers to adapt to a changing climate. There are other options available like drought-resistant seed that will be useful South Africa. Farmers can also practise drip irrigation to reduce water usage and water lot to evaporation.
However, farmers but be wary of maladaptation, Johnston warns. Fruit farmers erected shade cloths to protect their trees from the increased sunny days. Yet, it has been found that the shade cloths prevent bees from pollinating crops. So finding appropriate adaptation methods is very complicated.
Research into farming for the future shows that farmers will be more highly stressed. If they apply adaptations it may be expensive, but it will work out in the long run.