IMPACT OF PROJECTED CLIMATE CHANGE ON AGRICULTURAL PRODUCTION IN SEMI-ARID AREAS OF TANZANIA: A CASE OF SAME DISTRICT

Sub-Saharan Africa is one of the most vulnerable regions in the World to climate change because of widespread poverty and limited adaptive capacity. The future climate change is likely to present an additional challenge to the agricultural sector. Therefore, the effects of climate change on the current agronomic management practices were investigated using Same District, Tanzania as a case study area. APSIM software was used to investigate the response of maize ( Zea mays ) yield to different agronomic management practices using current and future (2046 - 2065) climate data. The climate change projections data from global climate models were downscaled using self-organising maps technique. Under the conventional practices, results show that during long rainy season (from March to May) there is yield decline of 13% for cultivar Situka, no change for cultivar Kito and increase of 10% and 15% for cultivars Sc401 and TMV1, respectively. Under the recommended practices, cultivars TMV1 and Sc401 are projected to register a 10% yield increase whereas cultivars Situka and Kito are projected to register a decrease of 10% and 45%, respectively. Also, under both conventional and recommended management practices, results showed that during short rainy season (from october to December/January) all cultivars are projected to register between 75% and 146% increase in maize yields. This implies that future climate change is going to have positive effects on current management practices during short rainy seasons and it will have negligible impact during long rainy seasons.L\u2019Afrique subsaharienne est une des r\ue9gions plus vuln\ue9rables au changement climatique au monde suite \ue0 la pauvret\ue9 g\ue9n\ue9ralis\ue9e et la capacit\ue9 d\u2019adaptation limit\ue9e. Dans l\u2019avenir, le changement climatique pr\ue9sentera probablement des d\ue9fis additionnels au secteur agricole. Pour ce faire, les effets du changement climatique sur les pratiques courantes de gestion agronomiques \ue9taient \ue9tudi\ue9s dans le district de Same en Tanzanie. Le logiciel APSIM \ue9tait utilis\ue9 en exploitant les donn\ue9es climatiques actuelles et futures (2046-2065), afin d\u2019\ue9valuer les effets des diff\ue9rentes pratiques agronomiques de gestion sur le rendement du ma\uefs ( Zea mays ). La projection des donn\ue9es de changement climatique \ue0 partir des mod\ue8les climatiques au niveau plan\ue9taire a \ue9t\ue9 r\ue9duite \ue0 l\u2019\ue9chelle \ue0 l\u2019aide de la technique d\u2019auto-organisation des cartes. Sous les pratiques conventionnelles, les r\ue9sultats montrent que durant la longue saison de pluie (du Mars au Mai) il ya eu diminution de 13% du rendement du cultivar Situka, augmentation 10% et 15% du rendement des cultivars Sc401 et TMV1, respectivement. Le cultivar Kito n\u2019a connu aucun changement de rendement. Sous les pratiques recommand\ue9es, les projections montrent que les cultivars TMV1 et Sc401 connaitront une augmentation de 10% de rendement pendant que les cultivars Situka et Kito enregistreront une baisse de rendement de 10% et 45%, respectivement. Aussi, sous les deux pratiques de gestion conventionnelles et recommand\ue9es, les r\ue9sultats de projections montrent que durant la courte saison de pluie (d\u2019octobre \ue0 D\ue9cembre/Janvier) tous les cultivars enregistreront une augmentation de rendements d\u2019entre 75% et 146%. Ceci impliquent des effets positifs du future changement climatique sur les pratiques courantes de gestion durant la courte saison de pluie et un effet n\ue9gligeable pendant la longue saison pluvieuse

Impact of projected climate change on agricultural production in semi-arid areas of Tanzania: a case of Same district

Sub-Saharan Africa is one of the most vulnerable regions in the World to climate change because of widespread poverty and limited adaptive capacity. The future climate change is likely to present an additional challenge to the agricultural sector. Therefore, the effects of climate change on the current agronomic management practices were investigated using Same District, Tanzania as a case study area. APSIM software was used to investigate the response of maize (Zea mays L.) yield to different agronomic management practices using current and future (2046 - 2065) climate data. The climate change projections data from global climate models were downscaled using self-organising maps technique. Under the conventional practices, results show that during long rainy season (from March to May) there is yield decline of 13% for cultivar Situka, no change for cultivar Kito and increase of 10% and 15% for cultivars Sc401 and TMV1, respectively. Under the recommended practices, cultivars TMV1 and Sc401 are projected to register a 10% yield increase whereas cultivars Situka and Kito are projected to register a decrease of 10% and 45%, respectively. Also, under both conventional and recommended management practices, results showed that during short rainy season (from October to December/January) all cultivars are projected to register between 75% and 146% increase in maize yields. This implies that future climate change is going to have positive effects on current management practices during short rainy seasons and it will have negligible impact during long rainy seasons.Thanks to Tanzania Meteorological Agency for provision of long-term climatic data for Same district. This project was funded by the Climate Change Adaptation in Africa (CCAA) programme, a joint initiative of Canada’s International Development Research Centre (IDRC) and the United Kingdom’s Department for International Development (DFID)

Economics of Rainwater Harvesting for Crop Enterprises in Semi-Arid Areas: The Case of Makanya Watershed in Pangani River Basin, Tanzania

Contrary to irrigated agriculture that uses blue water, rainwater harvesting that uses green water as direct rain (in-field management) and runoff (spate irrigation) has been accorded little importance in terms of economic research, investment, technology transfer and management. This paper demonstrates the economic benefits of rainwater management for crop production in a semi-arid Makanya Watershed in the Pangani River Basin. The results from two seasons (2003 to 2004) of yield monitoring for maize and lablab show that rainwater harvesting for crop production has the potential for poverty reduction. During the short rainy season of 2004, which was good (above average) in terms of runoff access, maize enterprise under macro-catchment rainwater harvesting realized yield, returns to land and labour amounting to 2.9 ton/ha, US $718/ha and US$19.5/person-day respectively. For the long rainy season of 2003, which was bad (below average), the performance of maize in terms of yield, returns to land and labour improved appreciably with increasing frequency of runoff reception for spate irrigation. Performance of maize and maize-lablab intercrop improved with increasing frequency of runoff access. Respective returns to land and labour under rainfed (no runoff) were only US $122.5/ha and US$3.3/person-day compared to US $1,011.9/ha and US$26.9/person-day with three incidences of runoff reception. Seasonal returns to land and labour exceed the national annual per caput income of US $280 and the global poverty line of US$1/person/day. These findings justify investment and technology transfer in rainwater harvesting for crop production in the upper watersheds of our major river basins

Adequacy of the current agronomic management strategies to cope with climate change : the case of Same district in Tanzania

Meeting: 11th WaterNet/WAFSA/GWP-SA Symposium 2010 IWRM for National and Regional Integration : Where Science, Policy and Practice Meet, 27-29 October 2010, Victoria Falls, ZimbabweSub-Saharan Africa is the most vulnerable region to climate change because of widespread poverty and limited adaptive capacity. The future climate change is likely to present an additional challenge to the agriculture sector. Therefore, the effects of climate change on the current agronomic management practices were investigated in Same District, Tanzania. APSIM software was used to investigate the response of maize yield on different agronomic management practices using the current and future climatic data. The climate change projections data from global climate models was downscaled using self-organizing maps technique. The yields of different maize varieties based on different sets of the current agronomic management strategies were simulated for the current and future climate (from 2046 to 2065). Under the conventional practices, the results showed that during the Masika season (from March to May) there will be a decline of 13% for cultivar Situka, no change for cultivar Kito, increase of 10% and 15% for cultivars Sc401 and TMV1, respectively. Under the recommended practices, cultivars TMV1 and Sc401 are projected to register a 10% increase whereas cultivars Situka and Kito are projected to register a decrease of 10% and 45%, respectively. Also, under both conventional and recommended management practices, results showed that during Vuli season (from October to December/January) all cultivars are projected to register between 75% and 146% increase in yields. The study concludes that the future climate change is going to have positive effects on the current management practices during Vuli season and negligible impact during Masika

Optimizing water and nitrogen application for neglected horticultural species in tropical sub-humid climate areas: a case of African eggplant (Solanum aethiopicum L.).

African eggplant, a traditional and important nutrient-dense crop to Tanzania’s nutrition and food security. However, yields remain low as a result of sub-optimal irrigation and fertilizer practices. To reduce the yield gap, a randomized split-plot design set up with irrigation as a main and nitrogen (N) treatments as a sub-factor. The irrigation regimes were 100 % (I100), 80 % (I80) and 60 % (I60) of crop water requirements whilst nitrogen levels were 250 kg N/ha (F100), 187 kg N/ha (F75), 125 kg N/ha (F50) and 0 kgN/ha (F0). The study evaluated the effect of irrigation water and N on crop growth variables and yield, fruit quality, WUE and NUE. The study showed the importance of combining different irrigation performance indicators which responds to different levels of water and nitrogen to evaluate and assess suitable irrigation and fertilizer strategies for African eggplant. The crop growth variables (plant height and LAI) had a good correlation with fruit yield (R2 = 0.6 and 0.8). The fruit quality was best performed by 100 % water in combination with 75 % N treatment. The best WUE and NUE was attained at 80 % and 100 % levels of water in combination with 75 % N. However, minimizing trade-offs between the various indicators, the optimal application for African eggplant would likely be around 80 % of the total irrigation requirement and 75 % of the N requirement in sandy clay loam soils under tropical sub-humid conditions

Economics of Rainwater Harvesting for Crop Enterprises in Semi-Arid Areas: The Case of Makanya Watershed in Pangani River Basin, Tanzania

Contrary to irrigated agriculture that uses blue water, rainwater harvesting that uses green water as direct rain (in-field management) and runoff (spate irrigation) has been accorded little importance in terms of economic research, investment, technology transfer and management. This paper demonstrates the economic benefits of rainwater management for crop production in a semi-arid Makanya Watershed in the Pangani River Basin. The results from two seasons (2003 to 2004) of yield monitoring for maize and lablab show that rainwater harvesting for crop production has the potential for poverty reduction. During the short rainy season of 2004, which was good (above average) in terms of runoff access, maize enterprise under macro-catchment rainwater harvesting realized yield, returns to land and labour amounting to 2.9 ton/ha, US $718/ha and US$19.5/person-day respectively. For the long rainy season of 2003, which was bad (below average), the performance of maize in terms of yield, returns to land and labour improved appreciably with increasing frequency of runoff reception for spate irrigation. Performance of maize and maize-lablab intercrop improved with increasing frequency of runoff access. Respective returns to land and labour under rainfed (no runoff) were only US $122.5/ha and US$3.3/person-day compared to US $1,011.9/ha and US$26.9/person-day with three incidences of runoff reception. Seasonal returns to land and labour exceed the national annual per caput income of US $280 and the global poverty line of US$1/person/day. These findings justify investment and technology transfer in rainwater harvesting for crop production in the upper watersheds of our major river basins