Impacts of Climate Variability and Change on Rainfed Sorghum and Maize: Implications for Food Security Policy in Tanzania

Abstract

Concern about food security has increased because of a changing climate, which poses a great threat to food crop productivity. Climate change projections from the Coupled Model Inter-comparison Project phase 5 (CMIP5) and crop models were used to investigate the impacts of climate change on rain-fed cereal production. Calibrated and evaluated crop models simulated maize and sorghum yields over time periods and scenarios across central zone Tanzania with and without adaptation. Simulation outputs without adaptation showed predominant decrease and increase in maize and sorghum yields, respectively. The results showed that maize yields were predicted to decline between 1% and 25% across periods, representative concentration pathways (RCPs) and global circulation models (GCMs). However, sorghum yields were on average predicted to increase between 5% and 21%. Overall when adaptation is incorporated toward mid-century, yields are projected to increase for both crops. The yield projections variation between cereal crops highlights the importance of location and crop specific climate change impact assessments. Despite the uncertainties in predicting the impacts of climate change on rainfed crops, especially on cereals (maize and sorghum) which are important staple food crops in semi-arid Tanzania, the findings of this study enable policy makers to develop plans aimed at sustainable food security. In conclusion, the results demonstrate the presumption that sorghum productivity stands a better chance than maize under prospects of negative impacts from climate change in central zone Tanzania.

Are Rainfall and Temperature Really Changing? Farmer’s Perceptions, Meteorological Data, and Policy Implications in the Tanzanian Semi-Arid Zone

“…In this aspect, the poor have a weak capacity to cope compared to the middle and upper classes. These results of the present study are in agreement with Ahmed et al [4] Below et al [7], Rowhani et al [8], Sieber et al [13], Msongaleli et al [17], and Cooper and Wheeler [22]. Despite little achievement in these adaptation strategies, much more should be done to improve the situation, as proposed by the respondents themselves in Table 4.…”

Yields of the Major Food Crops: Implications to Food Security and Policy in Tanzania’s Semi-Arid Agro-Ecological Zone

“…They further vetted extreme climate variability as a major cause of the crisis. The studies by Paavola [27] and Msongaleli et al [32] pointed out in favor of the farmers' observation. In addition, the results from interviews cemented on the same.…”

“…A study by Rowhani et al [25] and Msongaleli et al [32] on the impacts of climate change on cereal crops observed that crop failure is mostly caused by climate variability. They also indicated that, poor people are adversely impacted than the wealthy who are resilient to the dreadful condition.…”

Is dry soil planting an adaptation strategy for maize cultivation in semi-arid Tanzania?

“…The study region lies between latitudes 5°50′S to 6°10′S and between longitudes 35°40′E to 36°05′E, at an elevation of 1020 m above sea level. The dominant soil of the target region is defined as a ferralic Cambisol (FAO), which is low in fertility and seasonally waterlogged or flooded (Msongaleli et al 2015). Detailed information about the soil used in this assessment is presented in Table 1.…”