An assessment of maize production under different weather conditions (rainfall & temperature) in Wakiso district

Abstract

The climate patterns over Uganda particularly Wakiso district shows a high degree of spatial and temporal variability. The study main objective was to assess the variation of maize production under different weather conditions. Increasing trends for historical period (1998-2018) were observed in annual rainfall and both maximum and minimum temperatures, however constant increase were observed in both maximum and minimum temperatures compared to rainfall which had variations. Annual maize production for Wakiso district indicated positive increases with (gradient=128.6) and (R =0.70) over the historical period, however the trend of maize production was variable. Historical Mann Kendall results depict the same scenarios as trend and time series analysis, however, statistically significant trends where only observed in both maximum and minimum temperatures and maize production. Furthermore regression results showed positive weak linear relationship between rainfall and maize production which is statistically insignificant whereas both maximum and minimum temperatures depicted high positive linear relationships among maize which are statistically significant. 2 Climate sensitivity analysis results indicated that the WOFOST model is moderately sensitive to rainfall and this is because the WOFOST model assumes large amount of initial available soil water. However, sensitivity to both temperatures (minimum and maximum) is close to WOFOST maize production and the change in production as a result of temperature rise appears to be about the same. Projected maize production results depicted a variable increase in the projected maize production. There will be positive linear relationships between all the climate parameters under different climate scenarios and maize production, however these relationships will only be slightly significant under (T minimum RCP4.5, T minimum RCP8.5 and Rain RCP8.50) and weak positive linear relationships will occur under (T maximum RCP4.5, T maximum RCP8.5 and Rain RCP8.5. The results of coefficient of variation indicated lower projected Coefficient of Variations (≤ 20%) for all the climate parameters under the two scenarios over Wakiso district which will weakly deviated away from their mean values during the study period. Whereas CV value for the projected maize production is greater than 20% implying that there will be strong deviation in projected maize production away its mean value during the study period.