With South African farmers set to be hard at work by the end of this month in preparation of the 2018/19 summer crop production season, which starts next month, this seems like an appropriate moment to make a few comments about new planting challenges brought by changing weather patterns.
Climate change is one critical mega-trend that is affecting global agriculture in general, and South Africa’s agro-industry in particular. There are two fundamental aspects that underpin the weather factor in South Africa’s agricultural sector.
First, is the “inter-seasonal variation” in rainfall. The country now receives average annual rainfall that is comparatively lower than past trends. South Africa received an average of 526 mm of rainfall per year over the past 60 years. However, the recent past has seen a progressive decline in annual average rainfall, with the post-2010 average being 7% lower than the previous three decades (1970-2010).
Secondly, is the “intra-seasonal variation” in which the geographic and temporal distribution of rainfall seems to have shifted over time. Anecdotal evidence suggests a delay in the onset of the summer season. For example, the peak rainfall period in South Africa fell around early October in the eastern regions and from November in the western regions each year. Hence, the optimal plating period corresponded with this period (see chart below).
However, recent rainfall patterns have seen a three-to-six-week delay, which translates to a shift in optimal planting dates for summer crops such as maize and soybean.
As such, the farming sector has had to continuously adapt to this shift in order to ensure that planting coincides with peak rainfall patterns so that crops could receive sufficient moisture for seed germination and development. However, the farming sector has struggled not only due to the uncertainty in the onset of the seasonal peak (intra-seasonal variation), but also because of erratic and progressively lower rainfall (inter-seasonal variation).
Overall, the weather has been a major risk factor in the past few seasons, as rainfall patterns did not only change but were erratic, making it difficult for farmers to plan the planting schedules properly.
The early indications for the 2018/19 season suggest that this too could be a challenging season with a possibility of a drought that could be brought by El Niño. We will know more about this towards the end of this month.
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