**5. Conclusions**

The analysis of climate change impacts has shown that crop yield may be declined by as much as 65% by the end of the century in the Olifants catchment of South Africa. Yet, studies have also suggested that much of the yield loss can be mitigated using adaptation measures. In this paper, we used an ensemble of six biased corrected GCMs downscaled with one regional climate model to assess crop yield response to projected climate change (RCP 4.5 and RCP 8.5) for the Olifants catchment. The WEAP-MABIA processed-based crop model was used for yield prediction and to investigate the effect of adaptation strategies. The findings from the study revealed that surface temperature in the Olifants catchment will increase in the future while precipitation, on the other hand, is expected to decrease, which will consequently decline crop production. The analysis also revealed that soil with high water holding capacity tends to retain more water for crop use and thus is able to improve crop yield under limited rainfall.

Based on the adaptation strategies evaluated to cope with the impacts of climate change, the combination of changing sowing date with full irrigation application as well as the adoption of rainwater harvesting resulted in a significant positive yield change.

Finally, the effect of climate change on crop yield is considerable and poses serious threats not just to farmers but also to regional food security, especially given the rapidly growing population of South Africa which necessitates the production of more food. Ultimately, the solution to climate change lies in the effective deployment of adaptive strategies that could mitigate the impacts of climate change. This study thus provides

actionable knowledge and insights that could be used to avoid yield losses in the future. Adopting the measures proposed in this study are also well within the ability of policymakers and the majority of the smallholder farmers. The implications of the analysis and findings of this study are to pave the way towards a more proactive agricultural management planning with regards to climate change and its impending impacts on food security in the region.

**Author Contributions:** Conceptualization, M.F.O. and T.N.; Methodology, M.F.O.; Software, M.F.O.; Validation, M.F.O., T.N. and N.D.; Formal Analysis, M.F.O.; Investigation, M.F.O.; Resources, M.F.O.; Data Curation, T.N. and M.F.O.; Writing—Original Draft Preparation, M.F.O.; Writing—Review & Editing, T.N. and N.D.; Visualization, M.F.O.; Supervision, T.N. and N.D.; Funding Acquisition, M.F.O. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was supported by the Nation Research foundation-The World Academy of Science (NRF-TWAS) Grant No. 110823.

**Institutional Review Board Statement:** The study was conducted according to the guidelines of the Declaration of Mary Olabanji, and approved by the Institutional Review Ethics Committee of the University of Pretoria (protocol code NAS133/2019 and approval date 21-08-2019).

**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.

**Data Availability Statement:** Data available in a publicly accessible repository that does not issue DOIs. Publicly available datasets were analyzed in this study. This data can be found here: http://cordexesg.dmi.dk/esgf-web-fe/.

**Acknowledgments:** The authors wish to express their gratitude to the South African weather service for the provision of observed climate data used in this study.

**Conflicts of Interest:** Authors declare no conflict of interest.
