Browsing by Author "Rwehumbiza, Filbert"

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    Determinants of farm-level decisions regarding cereal crops and varieties in semi-arid Central Tanzania
    (Academic Journals, 2015) Msongaleli, Barnabas; Tumbo, Siza; Rwehumbiza, Filbert; Kihupi, Nganga
    We assess the potential and constraints of increased sorghum and pearl millet production to enhance food security and livelihoods in central Tanzania. These dryland cereals show a high potential to contribute to local food security. The study employed structured questionnaire survey as the main data collection method. Data analysis involved the use of Multinomial logit model (MNL) in combination with other descriptive statistics to determine the socio-economic and agro ecological variables influencing crop and variety choices and preferences. Empirical results revealed that age of the household head, farming experience, having plots on particular soil types and access to weather information significantly influence choices of cereal crops among sorghum, pearl millet and maize. On the same token, age, farming experience, farmer-extension contact and access to weather information were important factors on the choice of sorghum varieties viz. local landraces versus improved. Farmers’ perception results show that harvest and post-harvest processes, consumer tastes and preferences, and market access and prices strongly influence farmers’ decisions to grow sorghum. In conclusion the results show that although sorghum and pearl millet contribute to the food supply, perceptions, agro-ecological variables and socio-economic factors collectively constrain the realization of their potential in minimizing household food insecurity.
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    Impacts of climate variability and change on rainfed sorghum and maize: implications for food security policy in Tanzania
    (Canadian Center of Science and Education, 2015) Msongaleli, Barnabas M.; Rwehumbiza, Filbert; Tumbo, Siza D.; Kihupi, Nganga
    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.
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    Sorghum yield response to changing climatic conditions in semi-arid central Tanzania: evaluating crop simulation model applicability
    (Scientific Research Publishing, 2014) Msongaleli, Barnabas; Rwehumbiza, Filbert; Tumbo, Siza D.; Kihupi, Nganga
    Decision Support System for Agrotechnology Transfer (DSSAT) and Agricultural Production Systems SIMulator (APSIM) were calibrated and evaluated to simulate sorghum (Sorghum Bicolor L. Moench) var. Tegemeo under current and future climate in central Tanzania. Simulations for both current and future periods were run assuming present technology, current varieties and current agronomy packages to investigate rain-fed sorghum yield response. Simulations by both crop models using downscaled weather data from eight General Circulation Models (GCMs) under the Coupled Model Intercomparison Project phase 5 (CMIP5) and Representative Concentration Path- way (RCP 4.5) by mid-century show a mixture of increase and decrease in median sorghum yields. Four GCMs project yields to increase by 5% - 23.0% and one GCM show a decrease by 2% - 9%. Model simulations under the remaining three GCMs give contrasting results of increase and de-crease. Adjustment of crop duration to mimic the choice of growing local cultivars versus improved cultivars seems a feasible option under future climate scenarios. Our simulation results show that current open-pollinated sorghum cultivars would be resilient to projected changes in climate by 2050s but things seem better with long duration cultivars. We conclude that crop simulation models show their applicability as tools for assessing possible impacts of climate change on sorghum due to agreement in the direction of crop yield predictions in five out of eight selected GCMs under projected climate scenarios. The findings provide useful guidance and motivation to government authorities and development agencies dealing with food security issues to prioritize adaptations policies geared to ensuring increased and sustained sorghum productivity in Tanzania and elsewhere.