Impacts of climate variability and change on rainfed sorghum and maize: Implications for food security policy in Tanzania

Journal of Agricultural Science2015, Vol. 7(5)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

Impacts of climate variability and change on rainfed sorghum and maize: Implications for food security policy in Tanzania

Journal of Agricultural Science2015, Vol. 7(5)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

Improving the survivability of carrier networks to large-scale disasters

This chapter is dedicated to the description of methods aiming to improve the survivability of carrier networks to large-scale disasters. First, a disaster classification and associated risk analysis is described and the disaster-aware submarine fibre-optic cable deployment is addressed aiming to minimize the expected costs in case of natural disasters. Then, the chapter addresses the improvement of the network connectivity resilience to multiple node failures caused by malicious human activities. Two improvement methods are described aiming to minimize the connectivity impact of any set of node failures. One method is based on the appropriate selection of a set of network nodes to be made robust to node attacks. The other is a topology design method aiming to select the most appropriate set of links, within a given fibre budget, that provide the best resilience to multiple node failures. The latter method can also be applied to the upgrade task of a current network topology.publishe

Integrated assessment of climate change impacts and adaptation in agriculture: the case study of the Wami River Sub-basin, Tanzania

A Book chapter, Climate Variability and Change in Africa, Sustainable Development Goals Series, 115-136 pp.This study evaluates the impacts of climate change and an adaptation strategy on agricul- ture in the Wami River sub-basin in Tanzania. This study uses the Agricultural Model Improvement and Inter-comparison Project (AgMIP) framework that integrates climate, crops and economic models and data using a novel multi-model approach for impact assess- ment of agricultural systems under current and future conditions. This study uses five Global Circulation Models (GCMs) from the fifth phase of the Coupled Model Inter-comparison Project (CMIP5), two crop simulation models, and one economic impact assessment model. In this study, a representative agricultural path- ways (RAP) that characterises future condi- tions following ‘business-as-usual’ trends was developed and used to model future agricul- tural systems in the Wami River sub-basin. Results show that by mid-century, the maxi- mum and minimum temperatures will increase by 1.8–4.1 °C and 1.4–4.6 °C, respectively. Rainfall is predicted to be variable with some places projected to increase by 12%, while in other areas it is projected to decrease by 14– 28%. Maize yields under these conditions are projected to decrease by 5.3–40.7%. Results show that under current conditions, 50–60% of farm households are vulnerable to losses due to climate change. The impacts of climate change on poverty and per capita income are also projected to be negative. Under the current production system, poverty rates were pro- jected to increase by 0.8–15.3% and per-capita income to drop by 1.3–7.5%. Future socio-economic conditions and prices offset the negative impacts of climate change. Under future conditions, the proportion of households vulnerable to loss is estimated to range from 25 to 50%. Per-capita income and poverty rates are expected to improve under the future climate change conditions. Poverty rates would decrease between 1.9 and 11.2% and income per-capita would increase between 2.6 and 18.5%. The proposed future adaptation pack- age will further improve household liveli- hoods. This integrated assessment of climate change projections using the improved meth- ods and tools developed by AgMIP has con- tributed to a better understanding of climate change and adaptation impacts in a holistic manner

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

Agriculture has the greatest potential to lift the African continent out of poverty and alleviate hunger. Among the countries in sub-Saharan Africa, Tanzania has an abundance of natural resources and major agricultural potential. However, one of the most important constraints facing Tanzania’s agricultural sector is the dependence on unreliable and irregular weather, including rainfall. A strategy to cope with climate uncertainty in semi-arid regions is to proceed with the sowing of the crop before the onset of the rainy season. The advantage is that when the rains start, seeds are already in the soil and can begin immediately the process of germination. The objective of this paper was to assess the effectiveness of dry-soil planting for maize as an adaptation strategy in the context of a changing climate in Dodoma, a semi-arid region in Tanzania. For this assessment, the DSSAT crop model was used in combination with climate scenarios based on representative concentration pathways. A probability of crop failure of more than 80% can be expected when sowing occurs during the planting window (of 21 days) starting on 1st November. The next planting window we assessed, starting on 23rd November (which was still before the onset of rain), presented significantly lower probabilities of crop failure, indicating that sowing before the onset of the rainy season is a suitable adaptation strategy. Results also indicated that, despite not reaching the highest maize grain yields, fields prepared for dry-soil planting still produced adequate yields. The cultivation of several fields using the dry planting method is a strategy farmers can use to cope with low rainfall conditions, since it increases the chances of harvesting at least some of the cultivated fields. We conclude that dry-soil planting is a feasible and valid technique, even in scenarios of climate change, in order to provide acceptable maize yields in semi-arid Tanzania