Climate Variability and Change Disturbs Maize Production

Climate variability is expected to cause instability in the yield of the cultivated crops, which creating a high risk to global crops production. In Egypt, maize is one of the main cereal crops used as human food, where its flour mixed with wheat flour by 20% to produce bread. The breeding programs in Egypt were successful to produce high yielding and disease resistance maize hybrids possess yield stability traits. In this chapter, we analyzed the relationship between some weather elements (solar radiation, maximum and minimum temperatures, and relative humidity) and maize productivity in the five agro-climatic zones of Egypt from 2009 to 2021 using multiple linear regression analysis. The analysis of the studies weather elements and zonal- specific maize productivity revealed that maize is most suitable to grow in the fourth agro-climatic zone, because there was less fluctuation in its productivity there, compared to its value in the rest of the agro-climatic zones. The regression analysis between maize productivity and the studied weather elements suggested that the main seasonal weather elements affecting maize productivity in the five agro-climatic zones of Egypt are seasonal solar radiation in the first, second and fifth agro-climatic zones. The seasonal maximum temperature is also an affecting factor in maize productivity in the first, second and fourth agro-climatic zones. The seasonal minimum temperature was found to have an effect on maize productivity in the first, third and fifth agro-climatic zones. Seasonal relative humidity was found to be effective in the third agro-climatic zone only. Furthermore, the projected effect of climate change on maize productivity was assessed in the five agro-climatic zones of Egypt using CMIP6 mean projection of two future scenarios, namely SSP1-2.6 and SSP5-8.5 in two time-intervals (2060–2079 and 2080–2099), where maximum and minimum temperatures, as well as relative humidity were downloaded. Both scenarios projected a gradual increase in the maximum and minimum temperature from the first to the fifth agro-climatic zones, whereas seasonal relative humidity will be gradually decrease toward the fifth agro-climatic zone. The regression of the studied weather elements on maize productivity in the time period from 2009 to 2021 resulted in developing a zonal-specific prediction equations to be used in the projection of maize productivity in the future under the two scenarios. The results showed that maize productivity will be gradually reduced under both future climate scenarios, where the lowest reduction will occur in the first agro-climatic zone and the highest reduction will occur in the fifth agro-climatic zone. Additionally, a brief review was presented on the effect intercropping legume crops with maize on relieving the consequences of climate change on maize productivity.