*3.5. Maize Yield Trends*

Maize yield showed a positive trend in the three stations (Marquard, Clocolan and Senekal) increasing by different magnitudes. The maize yield in Marquard and Clocolan showed a positive trend increasing by 0.05- and 0.039-tons ha−1y−1, respectively. In Senekal, maize yield showed an increasing trend of 0.043 tons ha−<sup>1</sup> (Table 8).

**Table 8.** Annual maize yield trends during the study period from 1985–2016. MK Test Z denotes the Mann Kendall trend analysis test, and Q denotes 'the Sen's slope estimate'.


NB: \*\* denote significance when alpha = 0.01 and \* denote significance when alpha = 0.05.

Agroclimatic and maize yield variability in Sub-Saharan Africa (SSA) depends on the interactions between the combination of temperature, rainfall, and adaptive strategies [60]. The results from this study agree with other studies in SSA particularly with respect to temperatures and yield [61–66]. There were positive trends in all the stations for maize yield from 1985 to 2016 (Table 8). Marquard had the highest increasing trend of 0.05 tons ha−<sup>1</sup> year<sup>−</sup>1, followed by Senekal with 0.043 tons ha−<sup>1</sup> year−<sup>1</sup> and Clocolan with 0.039 tons ha−<sup>1</sup> year<sup>−</sup>1. This general positive trend agrees with those found by [40] on a comparative analysis of maize yields for South Africa. The average maize yield for Setsoto during the period of this study was between 1.96 tons ha−<sup>1</sup> to 2.89 tons ha−<sup>1</sup> per year with an inter-annual variability between 38–46% (Table 4). Even though no agronomic data are available for these locations, it seems logical that some of these increases could have been accounted for by changed farming practices e.g., the addition of more inorganic fertilizers and changed maize varieties. The maize yield in the Setsoto municipality is below the free-state provincial average maize yield of 3.8 tons ha−<sup>1</sup> [67] Maize production is said to be economically viable if 3.6 tons ha−<sup>1</sup> is produced [40,67], the data from this study showed that maize yield is below this limit. The yield trends in this study were low and it is only marginally economical to produce maize in these areas. The contribution to GDP from farming in the Setsoto municipality is decreasing [68,69] and it has been suggested that some farms are no longer being planted with maize or alternate crops. Yield variability was high across the stations, with Senekal having the highest variability of 46.1% per year and it also recorded the lowest yield among the stations.
