Effects of Rainfall Variability on Maize Production in Eswatini

Abstract

Crop production is increasingly under threat as rainfall becomes more erratic and unreliable due to climate change. The rainy season in Eswatini is mainly between October and March, but a variation in the amount of rainfall, onset and cessation of rainfall season, and dry spells has been lately threatening rain-fed maize production. This study was meant to assess the degree of rainfall variability and its impacts on rain-fed maize production in Eswatini. Rainfall data for the years 1991-2021 from six weather stations representing the various agro-ecological zones in Eswatini was obtained from the Department of Meteorological Services. The degree of rainfall variability was then determined using the coefficient of variability (CV). Also determined was the relationship between rainfall and the maize production. This was done to determine how maize production responds to rainfall variability.  Maize production data was obtained from the FAO online platform, FAOSTAT. Results from the study indicated that in Eswatini there is moderate to high rainfall variability. The Middleveld and Highveld had a year-to-year variability of 25% and 23%, respectively which is classified as moderate while the Lowveld had high variability of 34%. The seasonal rainfall was found to have a statistically significant relationship with nationwide maize production (in metric tonnes). The Pearson correlation coefficient (r) between seasonal rainfall and yield was found to be 0.68, which was tested and found to be significant (P<.05), indicating a significant positive correlation.