Accessing Future Mixed Beans Yield in Zambia under a Changing Climate Scenario
Author(s): Simfukwe Paul, Syampaku M. Edward, Daka Alfred
Quantitative evaluation of the response of crop yield and crop water productivity to future climate change is important to prevent/mitigate the adverse effects of climate change. This study assessed the future impact of climate change on rain-fed mixed beans production in Zambia. Mixed beans yield data from 1976 to 2000, was used, aggregated by province and was detrended for non-climatic factors, then correlated with the climatic variables from WABAL function in MOSAICC programme. The significantly correlated variables were regressed to generate coefficients (xi) for each variable (ai) and the intercept (b) to build models for each province. Downscaled data from three GCMs of CanESM2, CNRM-CM5 and MPI-ESM-MR were used to forecast the 2011-2069 yields under RCP 4.5 and RCP 8.5. By comparing the historical and the future mean yields for each RCP, the change was computed and judged for significance. The general trend in the projected climate simulated future yields by the three GCMs under the two RCPs showed a decrease in yield in Agro-Ecological Region (AER) III, IIb and I, and an increase in AER IIa. The projected decrease was attributed to the temperature increase and rainy seasons tending to start later and end earlier than the historical average. This change calls for use of varieties that are more resilient to elevated mean temperatures, use of early maturing varieties, selection of suitable planting dates, the use of chemical fertilizers and the construction of irrigation and water conservancy facilities.