Climate change impacts on rainfed maize yields in Zambia under conventional and optimized crop management

Abstract

Maize production in Zambia is characterized by significant yield gaps attributed to nutrient management and climate change threatens to widen these gaps unless agronomic management is optimized. Insights in the impacts of climate change on maize yields and the potential to mitigate negative impacts by crop management are currently lacking for Zambia. Using five Global Circulation models and the WOFOST crop model, we assessed climate change impacts on maize yields at a 0.5° × 0.5° spatial resolution for RCP 4.5 and RCP 8.5 scenarios. Impacts were assessed for the near future (2035-2066) and far future (2065-2096) in comparison with a reference period (1971-2001). The surface temperature and warm days (above 30 °C) are projected to increase strongly in the southern and western regions. Precipitation is expected to decline, except in the northern regions, whereas the number of wet days declines everywhere, shortening the growing season. The risk of crop failure in western and southern regions increases due to dry spells and heat stress, while crops in the northern regions will be threatened by flooding or waterlogging due to heavy precipitation. The simulated decline in the water-limited and water- and nutrient-limited maize yields varied from 15 to 20% in the near future and from 20 to 40% in the far future, mainly due to the expected temperature increases. Optimizing management by adjusting planting dates and maize variety selection can counteract these impacts by 6-29%. The existing gaps between water-limited and nutrient-limited maize yields are substantially larger than the expected yield decline due to climate change. Improved nutrient management is therefore crucial to boost maize production in Zambia.

Weather Extremes Shock Maize Production: Current Approaches and Future Research Directions in Africa

“…Some studies have tried to evaluate the adaptation options in specific sites or countries. For example, Siatwiinda et al [ 127 ] evaluated the roles of adaptation strategies with crop models at the national level. They found that although expected temperature and extremes led to a declining maize yield in Africa, the existing gaps between water-limited and nutrient-limited maize yield in Zambia are substantially larger than the expected yield decline due to climate change.…”

Effect of Nano Nitrogen and Nano Zinc on the Growth and Yield of Sweetcorn

“…Zn uptake in cob was varied from 16.76 to 69.37 g ha -1 whereas in stover it was found that it varied from 54.74 to 193.16 g ha -1 . It was observed that Zn uptake was more in case of stover than cob, may be due to balanced nutrition to crop which stimulate the metabolic activity resulting better growth which helping in utilization of nutrients absorbed by plant leading to dry matter production [14][15][16][17][18][19][20][21][22][23][24].…”

The 2020 Maize Production Failure in Ghana: A Case Study of Ejura-Sekyedumase Municipality

“…Evidence from the present study shows that increased dry spells, in terms of either longevity or frequency, pose a major risk to maize production in the transition zone of Ghana, and thus threaten its status as the breadbasket of the nation. In western and southern regions of Zambia, Siatwiinda, et al [14] found that the risk of maize failure is heightened by recurring dry conditions leading to heat stresses, but noted that production losses in the region are largely threatened by flooding conditions. In the case of Ejura-Sekyedumase Municipality, maize production losses were largely due to water stresses, but not flooding conditions.…”