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F. Graef
Humboldt Universität zu Berlin, Faculty of Life Sciences, Unter den Linden 6, 10099 Berlin, Germany

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Journal article
Published: 10 August 2019 in Sustainability
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Drought and heat-tolerant crops, such as Pearl millet (Pennisetum glaucum), are priority crops for fighting hunger in semi-arid regions. Assessing its performance under future climate scenarios is critical for determining its resilience and sustainability. Field experiments were conducted over two consecutive seasons (2015/2016 and 2016/2017) to determine the yield responses of the crop (pearl millet variety “Okoa”) to microdose fertilizer application in a semi-arid region of Tanzania. Data from the experiment were used to calibrate and validate the DSSAT model (CERES Millet). Subsequently, the model evaluated synthetic climate change scenarios for temperature increments and precipitation changes based on historic observations (2010–2018). Temperature increases of +0.5 to +3.0 °C (from baseline), under non-fertilized (NF) and fertilizer microdose (MD) conditions were used to evaluate nine planting dates of pearl millet from early (5 December) to late planting (25 February), based on increments of 10 days. The planting date with the highest yields was subjected to 49 synthetic scenarios of climate change for temperature increments and precipitation changes (of −30% up to +30% from baseline) to simulate yield responses. Results show that the model reproduced the phenology and yield, indicating a very good performance. Model simulations indicate that temperature increases negatively affected yields for all planting dates under NF and MD. Early and late planting windows were more negatively affected than the normal planting window, implying that temperature increases reduced the length of effective planting window for achieving high yields in both NF and MD. Farmers must adjust their planting timing, while the timely availability of seeds and fertilizer is critical. Precipitation increases had a positive effect on yields under all tested temperature increments, but Okoa cultivar only has steady yield increases up to a maximum of 1.5 °C, beyond which yields decline. This informs the need for further breeding or testing of other cultivars that are more heat tolerant. However, under MD, the temperature increments and precipitation change scenarios are higher than under NF, indicating a high potential of yield improvement under MD, especially with precipitation increases. Further investigation should focus on other cropping strategies such as the use of in-field rainwater harvesting and heat-tolerant cultivars to mitigate the effects of temperature increase and change in precipitation on pearl millet yield.

ACS Style

Festo Richard Silungwe; Frieder Graef; Sonoko Dorothea Bellingrath-Kimura; Emmanuel A Chilagane; Siza Donald Tumbo; Fredrick Cassian Kahimba; Marcos Alberto Lana. Modelling Rainfed Pearl Millet Yield Sensitivity to Abiotic Stresses in Semi-Arid Central Tanzania, Eastern Africa. Sustainability 2019, 11, 4330 .

AMA Style

Festo Richard Silungwe, Frieder Graef, Sonoko Dorothea Bellingrath-Kimura, Emmanuel A Chilagane, Siza Donald Tumbo, Fredrick Cassian Kahimba, Marcos Alberto Lana. Modelling Rainfed Pearl Millet Yield Sensitivity to Abiotic Stresses in Semi-Arid Central Tanzania, Eastern Africa. Sustainability. 2019; 11 (16):4330.

Chicago/Turabian Style

Festo Richard Silungwe; Frieder Graef; Sonoko Dorothea Bellingrath-Kimura; Emmanuel A Chilagane; Siza Donald Tumbo; Fredrick Cassian Kahimba; Marcos Alberto Lana. 2019. "Modelling Rainfed Pearl Millet Yield Sensitivity to Abiotic Stresses in Semi-Arid Central Tanzania, Eastern Africa." Sustainability 11, no. 16: 4330.

Journal article
Published: 19 July 2019 in Agronomy
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Rainfed agriculture constitutes around 80% of the world’s agricultural land, achieving the lowest on-farm crop yields and greatest on-farm water losses. Much of this land is in developing countries, including sub-Saharan Africa (SSA), where hunger is chronic. The primary constraint of rainfed agriculture—frequently experienced in SSA—is water scarcity, heightened by the unpredictability of season onset, erratic rainfall, as well as the inability of farmers to provide adequate soil and crop management. Farmers react differently to constraints, making a variety of choices—including the timing of planting, type of land cultivation, fertilization, and scattered fields, among many others. Limited information is available on the combined effects of these strategies for improving crop yield and water use efficiency (WUE). An experiment was co-conducted with farmers over four consecutive rainy seasons (2014–2018) in Tanzania, to evaluate these strategies for single and joint effects in improving yield and WUE on rainfed pearl millet (Pennisetum glaucum (L.) R.Br.). The treatments used were flat cultivation both without and with microdosing, as well as tied ridging without and with microdose interaction, with different planting dates depending on farmers’ decisions. Results show that farmers react differently to the early, normal, or late onset of the rainy season, and cumulative rainfall during its onset, which affects their decisions regarding planting dates, yield, and WUE. Microdose fertilization increases both the yield and WUE of pearl millet significantly, with greater effects obtained using tied ridging compared to flat cultivation. For low-income smallholder farmers in a semi-arid agroclimate, using tied ridging with microdosing during early planting is an effective response to spatiotemporal rainfall variability and poor soils.

ACS Style

Festo Richard Silungwe; Frieder Graef; Sonoko Dorothea Bellingrath-Kimura; Siza Donald Tumbo; Frederick Cassian Kahimba; Marcos Alberto Lana. The Management Strategies of Pearl Millet Farmers to Cope with Seasonal Rainfall Variability in a Semi-Arid Agroclimate. Agronomy 2019, 9, 400 .

AMA Style

Festo Richard Silungwe, Frieder Graef, Sonoko Dorothea Bellingrath-Kimura, Siza Donald Tumbo, Frederick Cassian Kahimba, Marcos Alberto Lana. The Management Strategies of Pearl Millet Farmers to Cope with Seasonal Rainfall Variability in a Semi-Arid Agroclimate. Agronomy. 2019; 9 (7):400.

Chicago/Turabian Style

Festo Richard Silungwe; Frieder Graef; Sonoko Dorothea Bellingrath-Kimura; Siza Donald Tumbo; Frederick Cassian Kahimba; Marcos Alberto Lana. 2019. "The Management Strategies of Pearl Millet Farmers to Cope with Seasonal Rainfall Variability in a Semi-Arid Agroclimate." Agronomy 9, no. 7: 400.

Journal article
Published: 20 March 2019 in Water
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Establishing food security in sub-Saharan African countries requires a comprehensive and high resolution understanding of the driving factors of crop production. Poor soil and adverse climate conditions are among the major drivers of poor regional crop production. Drought and rainfall variability challenges are not fully being addressed by rainfed producers in semiarid areas. In this study, we analysed the spatiotemporal rainfall variability (STRV) and its effects on pearl millet yield using two seasons of data collected from 38 rain gauge stations scattered randomly in farm plots within a 1500 ha area of semiarid central Tanzania. The STRV effects on pearl millet yield under flat and tied ridge management were analysed. Our results show that seasonal rainfall can vary significantly for neighboring fields at distances of less than 200 m, which impacts yield. The STRV for daily rainfall was found to be more critical than for total seasonal rainfall amounts. Scattering fields can help farmers avoid total harvest loss by obtaining at least some yield from the areas that received adequate rain. The use of tied ridges is recommended to conserve soil moisture and improve yields more than flat cultivation in semiarid areas.

ACS Style

Festo Richard Silungwe; Frieder Graef; Sonoko Dorothea Bellingrath-Kimura; Siza Donald Tumbo; Frederick Cassian Kahimba; Marcos Alberto Lana. Analysis of Intra and Interseasonal Rainfall Variability and Its Effects on Pearl Millet Yield in a Semiarid Agroclimate: Significance of Scattered Fields and Tied Ridges. Water 2019, 11, 578 .

AMA Style

Festo Richard Silungwe, Frieder Graef, Sonoko Dorothea Bellingrath-Kimura, Siza Donald Tumbo, Frederick Cassian Kahimba, Marcos Alberto Lana. Analysis of Intra and Interseasonal Rainfall Variability and Its Effects on Pearl Millet Yield in a Semiarid Agroclimate: Significance of Scattered Fields and Tied Ridges. Water. 2019; 11 (3):578.

Chicago/Turabian Style

Festo Richard Silungwe; Frieder Graef; Sonoko Dorothea Bellingrath-Kimura; Siza Donald Tumbo; Frederick Cassian Kahimba; Marcos Alberto Lana. 2019. "Analysis of Intra and Interseasonal Rainfall Variability and Its Effects on Pearl Millet Yield in a Semiarid Agroclimate: Significance of Scattered Fields and Tied Ridges." Water 11, no. 3: 578.

Articles
Published: 18 November 2018 in Communications in Soil Science and Plant Analysis
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Low, erratic rainfall amounts and restricted accessibility of chemical fertilizer for rural farmers in developing countries may have negative effects on crop production. Agricultural methods like biochar applications, fertilizer microdosing and tied ridging can help to mitigate these constraints, but have rarely been studied in combination and under varying water availability. A field trial was conducted in split-plot design over two contrasting cropping seasons in 2016 and 2017 in Tanzania to study the effect of these agricultural methods on maize grain yield, biomass, leaf area index, plant height and soil moisture content. In both seasons each with contrasting irrigation frequencies, fertilizer microdosing increased the grain yield of maize. Biochar alone affected the yield only at high application rates (10 t/ha) and low irrigation frequency. However, when combined with fertilizer microdosing the yield effect of biochar was more pronounced. For example, combining 5 t/ha biochar with fertilizer microdosing under flat tillage increased yield by 170% compared to the control without biochar and fertilizers. Tied ridges increased soil moisture content and tended to increase maize yield compared to flat tillage, whereas biochar application resulted in significantly higher soil moisture contents. Fertilizer microdosing with biochar application can be recommended to improve maize yields mainly under flat tillage.

ACS Style

H. Graef; D. Kiobia; P. Saidia; F. Kahimba; F. Graef; B. Eichler-Löbermann. Combined effects of biochar and fertilizer application on maize production in dependence on the cultivation method in a sub-humid climate. Communications in Soil Science and Plant Analysis 2018, 49, 2905 -2917.

AMA Style

H. Graef, D. Kiobia, P. Saidia, F. Kahimba, F. Graef, B. Eichler-Löbermann. Combined effects of biochar and fertilizer application on maize production in dependence on the cultivation method in a sub-humid climate. Communications in Soil Science and Plant Analysis. 2018; 49 (22):2905-2917.

Chicago/Turabian Style

H. Graef; D. Kiobia; P. Saidia; F. Kahimba; F. Graef; B. Eichler-Löbermann. 2018. "Combined effects of biochar and fertilizer application on maize production in dependence on the cultivation method in a sub-humid climate." Communications in Soil Science and Plant Analysis 49, no. 22: 2905-2917.

Journal article
Published: 27 September 2018 in Journal of Economics, Management and Trade
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ACS Style

P. S. Saidia; F. Graef; C. L. Rweyemamu; J. M. R. Semoka; A. A. Kimaro; L. Mwinuka; K. D. Mutabazi; S. Sieber. Nitrogen and Phosphorus Fertilizer Micro-doses on Maize and Its Effect on Profitability: An Evidence from Sub-humid Farming Systems, Tanzania. Journal of Economics, Management and Trade 2018, 21, 1 -10.

AMA Style

P. S. Saidia, F. Graef, C. L. Rweyemamu, J. M. R. Semoka, A. A. Kimaro, L. Mwinuka, K. D. Mutabazi, S. Sieber. Nitrogen and Phosphorus Fertilizer Micro-doses on Maize and Its Effect on Profitability: An Evidence from Sub-humid Farming Systems, Tanzania. Journal of Economics, Management and Trade. 2018; 21 (9):1-10.

Chicago/Turabian Style

P. S. Saidia; F. Graef; C. L. Rweyemamu; J. M. R. Semoka; A. A. Kimaro; L. Mwinuka; K. D. Mutabazi; S. Sieber. 2018. "Nitrogen and Phosphorus Fertilizer Micro-doses on Maize and Its Effect on Profitability: An Evidence from Sub-humid Farming Systems, Tanzania." Journal of Economics, Management and Trade 21, no. 9: 1-10.

Journal article
Published: 09 August 2018 in Land Use Policy
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Perception of the social, ecological and economic aspects of food security differs depending on the gender of the evaluating expert. Understanding these differences is key to developing upgrading strategies (UPS) that can help stabilise and enhance food security. This is highly relevant for research on food value chains (FVCs) in sub-Saharan Africa, where subsistence farmers are highly exposed to food insecurity. Prior to their implementation, however, the potential social, ecological and economic impacts of UPS in the target areas should be carefully assessed. This article reports on gender-based differences in perception and evaluates these differences using ex-ante impact assessments on the social, ecological, and economic aspects of food security and 13 UPS in the Tanzanian FVC that were carried out by agricultural scientists. The work is embedded in a larger multi-disciplinary research project. We find that impact assessments differed based on the gender of experts to various extents and depended on the types of criteria assessed. Female scientists were more careful during assessment, limiting themselves more strictly to the UPS and to criteria they were most knowledgeable in. Additionally, female respondents perceived the impacts of UPS on the economic and social sustainability of food security to be lower compared to their male colleagues. We therefore conclude that perceptions of female and male agricultural experts in strategy selection and implementation should be differentiated based on their gender. This may help reduce gender-specific challenges faced by African farmers.

ACS Style

F. Graef; G. Uckert. Gender determines scientists’ sustainability assessments of food-securing upgrading strategies. Land Use Policy 2018, 79, 84 -93.

AMA Style

F. Graef, G. Uckert. Gender determines scientists’ sustainability assessments of food-securing upgrading strategies. Land Use Policy. 2018; 79 ():84-93.

Chicago/Turabian Style

F. Graef; G. Uckert. 2018. "Gender determines scientists’ sustainability assessments of food-securing upgrading strategies." Land Use Policy 79, no. : 84-93.

Original paper
Published: 06 June 2018 in Systemic Practice and Action Research
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Upgrading local food value chains is a promising approach to invigorating African food systems. This endeavour warrants multi-disciplinary North-South collaboration and partnerships through participatory action research (PAR) to help leverage appropriate upgrading strategies (UPSs) with a focus on local stakeholders. The more disciplines, cultures, and partner institutions that are involved, the more a project will present challenges in terms of communication and coordinating activities. Our aim was to determine the costs and investigate whether PAR with a multi-disciplinary approach was feasible in rural Tanzania with over 600 local stakeholders and more than 100 scientists. This article presents a self-evaluation of the collaboration and communication of project scientists during their research activities. Despite the overall high satisfaction, the more complex and complicated PAR activities required more cooperation, instructions and communication among the project scientists than had been anticipated in this multi-disciplinary, multi-cultural, and multi–institutional context, resulting in greater tension and dissatisfaction. The findings indicate that this type of large multi-disciplinary PAR is challenging in terms of flexibility in the planning of research activities, the administration of finances, and cross-cultural communication. Potential avenues to overcome these obstacles include a) more communication on PAR activities across cultures to develop a shared vocabulary; b) developing other modes of shared responsibility for a more horizontal collaboration; and c) more face-to-face cross-cultural activities to overcome cultural, disciplinary and geographical distance.

ACS Style

F. Graef; K. D. Mutabazi; S. Sieber; Folkard Asch; B. Makoko; M. Bonatti; M. Brüntrup; C. Gornott; Ludger Herrmann; L. Kaburire; F. C. Kahimba; A. Kimaro; A. Kuntosch; H. J. König; P. Lagwen; M. A. Lana; C. Lambert; C. Levy; K. Löhr; C. Maeda; H. Mbwana; D. Mchau; M. T. Mnimbo; S. Munder; L. Mwinuka; P. Ngwenya; E. Nickson; E. Nkonya; P. Saidia; M. P. Schäfer; J. Schindler; V. Silayo; Götz Bernhard Uckert; J. Wambura; L. William. Multi-Disciplinary North-South Collaboration in Participatory Action Research on Food Value Chains: a German-Tanzanian Case Study on Perceptions, Experiences and Challenges. Systemic Practice and Action Research 2018, 32, 359 -378.

AMA Style

F. Graef, K. D. Mutabazi, S. Sieber, Folkard Asch, B. Makoko, M. Bonatti, M. Brüntrup, C. Gornott, Ludger Herrmann, L. Kaburire, F. C. Kahimba, A. Kimaro, A. Kuntosch, H. J. König, P. Lagwen, M. A. Lana, C. Lambert, C. Levy, K. Löhr, C. Maeda, H. Mbwana, D. Mchau, M. T. Mnimbo, S. Munder, L. Mwinuka, P. Ngwenya, E. Nickson, E. Nkonya, P. Saidia, M. P. Schäfer, J. Schindler, V. Silayo, Götz Bernhard Uckert, J. Wambura, L. William. Multi-Disciplinary North-South Collaboration in Participatory Action Research on Food Value Chains: a German-Tanzanian Case Study on Perceptions, Experiences and Challenges. Systemic Practice and Action Research. 2018; 32 (4):359-378.

Chicago/Turabian Style

F. Graef; K. D. Mutabazi; S. Sieber; Folkard Asch; B. Makoko; M. Bonatti; M. Brüntrup; C. Gornott; Ludger Herrmann; L. Kaburire; F. C. Kahimba; A. Kimaro; A. Kuntosch; H. J. König; P. Lagwen; M. A. Lana; C. Lambert; C. Levy; K. Löhr; C. Maeda; H. Mbwana; D. Mchau; M. T. Mnimbo; S. Munder; L. Mwinuka; P. Ngwenya; E. Nickson; E. Nkonya; P. Saidia; M. P. Schäfer; J. Schindler; V. Silayo; Götz Bernhard Uckert; J. Wambura; L. William. 2018. "Multi-Disciplinary North-South Collaboration in Participatory Action Research on Food Value Chains: a German-Tanzanian Case Study on Perceptions, Experiences and Challenges." Systemic Practice and Action Research 32, no. 4: 359-378.

Research article
Published: 04 May 2018 in PLOS ONE
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Research and development increasingly apply participatory approaches that involve both stakeholders and scientists. This article presents an evaluation of German and Tanzanian researchers’ perceptions during their activities as part of a large interdisciplinary research project in Tanzania. The project focused on prioritizing and implementing food-securing upgrading strategies across the components of rural food value chains. The participants involved during the course of the project were asked to provide feedback on 10 different research steps and to evaluate eight core features related to the functioning and potential shortcomings of the project. The study discriminated among evaluation differences linked to culture, gender, and institutional status. Perceptions differed between Tanzanian and German participants depending on the type and complexity of the participatory research steps undertaken and the intensity of stakeholder participation. There were differences in perception linked to gender and hierarchical status; however, those differences were not as concise and significant as those linked to nationality. These findings indicate that participatory action research of this nature requires more targeted strategies and planning tailored to the type of activity. Such planning would result in more efficient and satisfactory communication, close collaboration, and mutual feedback to avoid conflicts and other problems. We further conclude that it would be advisable to carefully incorporate training on these aspects into future project designs.

ACS Style

Frieder Graef; Stefan Sieber. Cultural background, gender, and institutional status have an effect on the evaluation of multi-disciplinary participatory action research. PLOS ONE 2018, 13, e0196790 .

AMA Style

Frieder Graef, Stefan Sieber. Cultural background, gender, and institutional status have an effect on the evaluation of multi-disciplinary participatory action research. PLOS ONE. 2018; 13 (5):e0196790.

Chicago/Turabian Style

Frieder Graef; Stefan Sieber. 2018. "Cultural background, gender, and institutional status have an effect on the evaluation of multi-disciplinary participatory action research." PLOS ONE 13, no. 5: e0196790.

Communication
Published: 22 April 2018 in Water
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Climatic and environmental changes are expected to affect in particular those regions where the economy is primarily based on the agricultural sector and where the dependency on water availability is high. This study examines how smallholder farmers in rural Tanzania perceived climatic and environmental changes over the past 20 years and the resulting effects on water availability and food security. The study is based on a household survey of 899 farmers in a semi-arid and a sub-humid region in Tanzania. It was found that (a) significant differences in perceptions of the environment by farmers can be attributed to agro-climatic location, while the distance to a water source has less impact on individual perception; (b) differently perceived changes affect individual water availability and food security; and (c) the farm level adaptation methods applied are linked to vulnerability to changes and the household dependence on the immediate environment. The authors conclude that the specific environmental surroundings paired with socio-economic factors can severely compound the negative effects of water scarcity on rural farmers.

ACS Style

Lina Röschel; Frieder Graef; Ottfried Dietrich; Meike Pendo Schäfer; Dagmar Haase. Individual Local Farmers’ Perceptions of Environmental Change in Tanzania. Water 2018, 10, 525 .

AMA Style

Lina Röschel, Frieder Graef, Ottfried Dietrich, Meike Pendo Schäfer, Dagmar Haase. Individual Local Farmers’ Perceptions of Environmental Change in Tanzania. Water. 2018; 10 (4):525.

Chicago/Turabian Style

Lina Röschel; Frieder Graef; Ottfried Dietrich; Meike Pendo Schäfer; Dagmar Haase. 2018. "Individual Local Farmers’ Perceptions of Environmental Change in Tanzania." Water 10, no. 4: 525.

Review
Published: 22 March 2018 in Water
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Spatiotemporal rainfall variability and low soil fertility are the primary crop production challenges facing poor farmers in semi-arid environments. However, there are few solutions for addressing these challenges. The literature provides several crop upgrading strategies (UPS) for improving crop yields, and biophysical models are used to simulate these strategies. However, the suitability of UPS is limited by systemization of their areas of application and the need to cope with the challenges faced by poor farmers. In this study, we reviewed 187 papers from peer-reviewed journals, conferences and reports that discuss UPS suitable for cereals and biophysical models used to assist in the selection of UPS in semi-arid areas. We found that four UPS were the most suitable, namely tied ridges, microdose fertilization, varying sowing dates, and field scattering. The DSSAT, APSIM and AquaCrop models adequately simulate these UPS. This work provides a systemization of crop UPS and models in semi-arid areas that can be applied by scientists and planners.

ACS Style

Festo Richard Silungwe; Frieder Graef; Sonoko Dorothea Bellingrath-Kimura; Siza Donald Tumbo; Frederick Cassian Kahimba; Marcos Alberto Lana. Crop Upgrading Strategies and Modelling for Rainfed Cereals in a Semi-Arid Climate—A Review. Water 2018, 10, 356 .

AMA Style

Festo Richard Silungwe, Frieder Graef, Sonoko Dorothea Bellingrath-Kimura, Siza Donald Tumbo, Frederick Cassian Kahimba, Marcos Alberto Lana. Crop Upgrading Strategies and Modelling for Rainfed Cereals in a Semi-Arid Climate—A Review. Water. 2018; 10 (4):356.

Chicago/Turabian Style

Festo Richard Silungwe; Frieder Graef; Sonoko Dorothea Bellingrath-Kimura; Siza Donald Tumbo; Frederick Cassian Kahimba; Marcos Alberto Lana. 2018. "Crop Upgrading Strategies and Modelling for Rainfed Cereals in a Semi-Arid Climate—A Review." Water 10, no. 4: 356.

Journal article
Published: 01 January 2018 in Environmental Impact Assessment Review
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ACS Style

F. Graef; L.E.A. Hernandez; Hannes J. König; Götz Bernhard Uckert; M.T. Mnimbo. Systemising gender integration with rural stakeholders' sustainability impact assessments: A case study with three low-input upgrading strategies. Environmental Impact Assessment Review 2018, 68, 81 -89.

AMA Style

F. Graef, L.E.A. Hernandez, Hannes J. König, Götz Bernhard Uckert, M.T. Mnimbo. Systemising gender integration with rural stakeholders' sustainability impact assessments: A case study with three low-input upgrading strategies. Environmental Impact Assessment Review. 2018; 68 ():81-89.

Chicago/Turabian Style

F. Graef; L.E.A. Hernandez; Hannes J. König; Götz Bernhard Uckert; M.T. Mnimbo. 2018. "Systemising gender integration with rural stakeholders' sustainability impact assessments: A case study with three low-input upgrading strategies." Environmental Impact Assessment Review 68, no. : 81-89.

Accepted manuscript
Published: 28 November 2017 in Environmental Research Letters
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In Tanzania, a majority of rural residents cook using firewood-based three-stone-fire stoves. In this study, quantitative performance differences between technologically advanced Improved Cooking Stoves and three-stone-fire stoves are analyzed. We test the performance of Improved Cooking Stoves and three-stone-fire stoves using local cooks, foods, and fuels, in the semi-arid region of Dodoma in Tanzania. We used the cooking protocol of the Controlled Cooking Test following a two-pot test design. The findings of the study suggest that Improved Cooking Stoves use less firewood and less time than three-stone-fire stoves to conduct a predefined cooking task. In total, 40 households were assessed and ask to complete two different cooking tasks: (1) A fast cooking meal (rice and vegetables) and (2) a slow cooking meal (beans and rice). For cooking task 1, the results show a significant reduction in firewood consumption of 37.1% by Improved Cooking Stoves compared to traditional three-stone-fire stoves; for meal 2 a reduction of 15.6% is found. In addition, it was found that the time needed to conduct cooking tasks 1 and 2 was significantly reduced by 26.8%, respectively 22.8%, when Improved Cooking Stoves were used instead of three-stone-fire-stoves. We observed that the villagers altered the initial ICS design, resulting in the so-called modified ICS. In an additional Controlled Cooking Test we conducted cooking task 3: A very fast cooking meal (maize flour and vegetables) within 32 households. Significant changes between the initial and modified ICS regarding firewood and time consumption was not detected. However, analyses show that both firewood and time consumption during cooking was reduced when large amounts (6-7 household members) of food were prepared instead of small amounts (2-3 household members).

ACS Style

J Hafner; G Uckert; F Graef; H Hoffmann; A A Kimaro; O Sererya; S Sieber. A quantitative performance assessment of improved cooking stoves and traditional three-stone-fire stoves using a two-pot test design in Chamwino, Dodoma, Tanzania. Environmental Research Letters 2017, 13, 025002 .

AMA Style

J Hafner, G Uckert, F Graef, H Hoffmann, A A Kimaro, O Sererya, S Sieber. A quantitative performance assessment of improved cooking stoves and traditional three-stone-fire stoves using a two-pot test design in Chamwino, Dodoma, Tanzania. Environmental Research Letters. 2017; 13 (2):025002.

Chicago/Turabian Style

J Hafner; G Uckert; F Graef; H Hoffmann; A A Kimaro; O Sererya; S Sieber. 2017. "A quantitative performance assessment of improved cooking stoves and traditional three-stone-fire stoves using a two-pot test design in Chamwino, Dodoma, Tanzania." Environmental Research Letters 13, no. 2: 025002.

Letter
Published: 21 November 2017 in Environmental Research Letters
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Enhancing food security is one of the main goals of subsistence farmers in Sub-Saharan Africa. This study investigates the implementation of improved loam-made cooking stoves and its contribution to coping and livelihood strategies. Controlled combustion, air as well as smoke flue, and heat insulation facilitate the more efficient fuel consumption of improved cooking stoves compared to traditional stoves—namely three stone fires. Although the majority of small-scale farmers in Sub-Saharan Africa rely on the free public good of firewood, the increasing time needed for collecting firewood implies high opportunity costs for productive members of the family. The primary outcomes for users of improved stoves are reduced fuel consumption, greater safety, saved time, and reduced smoke in the kitchen. The paper illustrates part of the output, outcome, and impact of a participatory action research approach for implementing improved cooking stoves. Special emphasis was put on enabling the villagers to construct their stoves without external support, hence having locally manufactured stoves made of mud, bricks, and dried grass. The impact pathway of improved cooking stoves followed the training-of-trainers concept, where members of the initially established farmer groups were trained to construct stoves on their own. Special focus was given to knowledge exchange and knowledge transfer in order to increase firewood efficiency and overall satisfaction of users of improved cook stoves. Encouraging the members to further adapt the stoves enabled them to scale-up the construction of improved cooked stoves into a business model and increase dissemination while creating income. Although many important benefits, like time and knowledge gain, were identified by the farmers after adoption of the new technology, we found adoption rates differed significantly between regions.

ACS Style

G Uckert; J Hafner; F Graef; H Hoffmann; A Kimaro; O Sererya; S Sieber. Farmer innovation driven by needs and understanding: building the capacities of farmer groups for improved cooking stove construction and continued adaptation. Environmental Research Letters 2017, 12, 125001 .

AMA Style

G Uckert, J Hafner, F Graef, H Hoffmann, A Kimaro, O Sererya, S Sieber. Farmer innovation driven by needs and understanding: building the capacities of farmer groups for improved cooking stove construction and continued adaptation. Environmental Research Letters. 2017; 12 (12):125001.

Chicago/Turabian Style

G Uckert; J Hafner; F Graef; H Hoffmann; A Kimaro; O Sererya; S Sieber. 2017. "Farmer innovation driven by needs and understanding: building the capacities of farmer groups for improved cooking stove construction and continued adaptation." Environmental Research Letters 12, no. 12: 125001.

Journal article
Published: 12 June 2017 in International Journal of Conflict Management
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This paper aims to analyze the transferability of a conflict management model developed for business organizations to a temporary and international research project to serve as a support tool for internal communication and in case of conflict. The authors analyze the transferability of a conflict management model that was initially developed for business organizations to an international, inter-organizational and temporary research project that is third-party funded. Using a case study, a participatory approach is applied with both qualitative and quantitative methods used. The transferability is possible but only with the adaption of conflict prevention. The project’s international and inter-organizational structure further results in a need for decentralization of conflict management responsibilities and diversification of conflict management approaches. Time, financial resources and a high autonomy of cooperation partners limit the degree of participation in the design process. The research is based on a case study. Research on comparative design processes are needed to verify or extrapolate findings and to help assess the impact of conflict management systems in other large research projects. This paper contributes to the body of knowledge on conflict management systems. By implementing a conflict management system in a temporary, international and scientific project environment, this case study identifies contextual factors relevant for the system design and provides initial test results. As conflict management systems in research projects are not yet prominent, this adapted model of conflict prevention and management can benefit similar projects.

ACS Style

Katharina Löhr; Frieder Graef; Michelle Bonatti; Henry F. Mahoo; Jane Wambura; Stefan Sieber. Conflict management systems for large scientific research projects. International Journal of Conflict Management 2017, 28, 322 -345.

AMA Style

Katharina Löhr, Frieder Graef, Michelle Bonatti, Henry F. Mahoo, Jane Wambura, Stefan Sieber. Conflict management systems for large scientific research projects. International Journal of Conflict Management. 2017; 28 (3):322-345.

Chicago/Turabian Style

Katharina Löhr; Frieder Graef; Michelle Bonatti; Henry F. Mahoo; Jane Wambura; Stefan Sieber. 2017. "Conflict management systems for large scientific research projects." International Journal of Conflict Management 28, no. 3: 322-345.

Original paper
Published: 10 June 2017 in Food Security
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Upgrading strategies for a given product value chain might not result in the intended impact on different gender groups, if gender analysis is not undertaken. This study investigated the gender influence on preferred food and cash crops, as well as upgrading strategies in sub-humid Kilosa and semi-arid Chamwino Districts, Tanzania. A mixed methods research design was used to collect information from 595 respondents, while content analysis was used to qualitatively analyze qualitative data obtained from focus group discussions and key informant interviews. Our findings show that farmers from Kilosa and Chamwino had no differences with respect to preferences expressed by men and women for their first priority cash. Gender differences for choices were evident in relation to the second priority, food crops, in the semi-arid area and the third priority, which was also food crops in the sub-humid area, where women and youth differed from men on their views toward maize versus sorghum in the semi-arid region. Here, youth differed from women and men in how they viewed cassava versus rice. For upgrading strategies, which were only conducted with the first priority crops, most of the strategies preferred by men differed from those preferred by women and youth. In both areas, youth and women preferred upgrading strategies related to crop harvesting, transportation and primary processing, whereas men preferred upgrading strategies for farm inputs and crop marketing. Therefore, it is recommended that site-specific gendered analysis on upgrading strategies in agricultural value chains should be completed prior to introducing an intervention.

ACS Style

T. S. Mnimbo; J. Lyimo-Macha; J. K. Urassa; H. F. Mahoo; S. D. Tumbo; F. Graef. Influence of gender on roles, choices of crop types and value chain upgrading strategies in semi-arid and sub-humid Tanzania. Food Security 2017, 9, 1173 -1187.

AMA Style

T. S. Mnimbo, J. Lyimo-Macha, J. K. Urassa, H. F. Mahoo, S. D. Tumbo, F. Graef. Influence of gender on roles, choices of crop types and value chain upgrading strategies in semi-arid and sub-humid Tanzania. Food Security. 2017; 9 (6):1173-1187.

Chicago/Turabian Style

T. S. Mnimbo; J. Lyimo-Macha; J. K. Urassa; H. F. Mahoo; S. D. Tumbo; F. Graef. 2017. "Influence of gender on roles, choices of crop types and value chain upgrading strategies in semi-arid and sub-humid Tanzania." Food Security 9, no. 6: 1173-1187.

Journal article
Published: 01 September 2016 in Environmental Impact Assessment Review
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The objective of this paper was to assess the sustainability impacts of planned agricultural development interventions, so called upgrading strategies (UPS), to enhance food security and to identify what advantages and risks are assessed from the farmer's point of view in regards to social life, the economy and the environment. We developed a participatory methodological procedure that links food security and sustainable development. Farmers in four different case study villages in rural Tanzania chose their priority UPS. For these UPS, they assessed the impacts on locally relevant food security criteria. The positive impacts identified were mainly attributed to increased agricultural production and its related positive impacts such as increased income and improved access to necessary means to diversify the diet. However, several risks of certain UPS were also indicated by farmers, such as increased workload, high maintenance costs, higher competition among farmers, loss of traditional knowledge and social conflicts. We discussed the strong interdependence of socio-economic and environmental criteria to improve food security for small-scale farmers and analysed several trade-offs in regards to UPS choices and food security criteria. We also identified and discussed the advantages and challenges of our methodological approach. In conclusion, the participatory impact assessment on the farmer level allowed a locally specific analysis of the various positive and negative impacts of UPS on social life, the economy and the environment. We emphasize that only a development approach that considers social, economic and environmental challenges simultaneously can enhance food security.

ACS Style

Jana Schindler; Frieder Graef; Hannes Jochen König; Devotha Mchau; Paul Saidia; Stefan Sieber. Sustainability impact assessment to improve food security of smallholders in Tanzania. Environmental Impact Assessment Review 2016, 60, 52 -63.

AMA Style

Jana Schindler, Frieder Graef, Hannes Jochen König, Devotha Mchau, Paul Saidia, Stefan Sieber. Sustainability impact assessment to improve food security of smallholders in Tanzania. Environmental Impact Assessment Review. 2016; 60 ():52-63.

Chicago/Turabian Style

Jana Schindler; Frieder Graef; Hannes Jochen König; Devotha Mchau; Paul Saidia; Stefan Sieber. 2016. "Sustainability impact assessment to improve food security of smallholders in Tanzania." Environmental Impact Assessment Review 60, no. : 52-63.

Research article
Published: 01 September 2015 in Outlook on Agriculture
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Food security is one of the main goals of rural poor people. To enhance food security in this context, participatory action research can help to ensure sustained success while considering entire food value chains (FVC). This paper assesses the feasibility and potential success of upgrading strategies (UPS) as well as their assessment criteria as developed by German and Tanzanian agricultural scientists. The results form part of a larger participatory research project conducted in two climatically representative regions of Tanzania: semi-arid Dodoma and subhumid Morogoro. This paper presents the findings with respect to food processing, waste management and bioenergy, along with income generation and market participation. Assessments on other components of the FVC, including natural resource management, crop production and consumption, are reported by Graef et al (2015). The assessments for food processing revealed preferences for preservation techniques, oil extraction processes and food storage devices for the semi-arid region. In contrast, in the subhumid region, the experts favoured food storage devices and preservation techniques. Assessments of waste management and bioenergy UPS for both regions indicated the importance of animal feed from crop residues, crop residues as mulch and compost from food waste, although with somewhat different priorities. Assessments on income generation and markets in both regions revealed preferences for savings and credit cooperatives and communication techniques, but also indicated that warehouse receipt systems and guarantee systems had a high impact. Assessments differed between the two different climatic regions, and to some extent also between the nationality of experts and their gender. The authors therefore attach importance to integrating different South–North and female–male awareness in assessments among scientists. Moreover, local and/or regional stakeholders and experts should be involved in developing site-adapted UPS for enhancing FVCs.

ACS Style

F. Graef; I. Schneider; A. Fasse; J.U. Germer; E. Gevorgyan; F. Haule; Harry Hoffmann; F.C. Kahimba; L. Kashaga; L. Kissoly; C. Lambert; Marcos Lana; H.F. Mahoo; B. Makoko; S.H. Mbaga; A. Mmbughu; S. Mkangwa; L. Mrosso; K.D. Mutabazi; L. Mwinuka; H. Ngazi; E. Nkonya; S. Said; A. Schaffert; M.P. Schäfer; J. Schindler; S. Sieber; M. Swamila; H.M. Welp; L. William; Y.M. Yustas. Assessment of Upgrading Strategies to Improve Regional Food Systems in Tanzania. Outlook on Agriculture 2015, 44, 179 -186.

AMA Style

F. Graef, I. Schneider, A. Fasse, J.U. Germer, E. Gevorgyan, F. Haule, Harry Hoffmann, F.C. Kahimba, L. Kashaga, L. Kissoly, C. Lambert, Marcos Lana, H.F. Mahoo, B. Makoko, S.H. Mbaga, A. Mmbughu, S. Mkangwa, L. Mrosso, K.D. Mutabazi, L. Mwinuka, H. Ngazi, E. Nkonya, S. Said, A. Schaffert, M.P. Schäfer, J. Schindler, S. Sieber, M. Swamila, H.M. Welp, L. William, Y.M. Yustas. Assessment of Upgrading Strategies to Improve Regional Food Systems in Tanzania. Outlook on Agriculture. 2015; 44 (3):179-186.

Chicago/Turabian Style

F. Graef; I. Schneider; A. Fasse; J.U. Germer; E. Gevorgyan; F. Haule; Harry Hoffmann; F.C. Kahimba; L. Kashaga; L. Kissoly; C. Lambert; Marcos Lana; H.F. Mahoo; B. Makoko; S.H. Mbaga; A. Mmbughu; S. Mkangwa; L. Mrosso; K.D. Mutabazi; L. Mwinuka; H. Ngazi; E. Nkonya; S. Said; A. Schaffert; M.P. Schäfer; J. Schindler; S. Sieber; M. Swamila; H.M. Welp; L. William; Y.M. Yustas. 2015. "Assessment of Upgrading Strategies to Improve Regional Food Systems in Tanzania." Outlook on Agriculture 44, no. 3: 179-186.

Research article
Published: 01 June 2015 in Outlook on Agriculture
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Sustainable rural food systems for poor and vulnerable people need to be locally adapted to enhance food security. This requires participatory action research that considers the entire food value chain (FVC). This paper presents an assessment of the feasibility and potential success of upgrading strategies (UPS) for enhancing food security based on a study that was part of a larger participatory research project in two regions of Tanzania. The authors present the results relating to natural resource management and crop production. The results for natural resources show that enhanced soil water management was rated as high for the semi-arid Dodoma region. For the Morogoro region, the experts favoured soil fertility-improving UPS, such as conservation agriculture and agroforestry. Assessments of food production for both regions indicated the importance of intercropping, manure input, pest and disease control and cover crops. Assessments differed greatly between the two different climatic regions, and to a lesser extent between the nationality of the experts and their gender. This highlights the importance of including different South–North and female–male awareness in assessments. Implementation feasibility assessments of UPS indicated that the most suitable approaches were rainwater harvesting for semi-arid and conservation agriculture for subhumid regions respectively. Local and/or regional stakeholders and experts should be involved in developing and assessing site-adapted UPS for enhancing Tanzanian FVCs.

ACS Style

F. Graef; I. Schneider; A. Fasse; J.U. Germer; E. Gevorgyan; F. Haule; Harry Hoffmann; F.C. Kahimba; L. Kashaga; L. Kissoly; C. Lambert; M. Lana; H.F. Mahoo; B. Makoko; S.H. Mbaga; A. Mmbughu; S. Mkangwa; L. Mrosso; K.D. Mutabazi; L. Mwinuka; H. Ngazi; E. Nkonya; C. Reif; S. Said; A. Schaffert; M.P. Schäfer; J. Schindler; S. Sieber; M. Swamila; H.M. Welp; L. William; Y.M. Yustas. Natural Resource Management and Crop Production Strategies to Improve Regional Food Systems in Tanzania. Outlook on Agriculture 2015, 44, 159 -167.

AMA Style

F. Graef, I. Schneider, A. Fasse, J.U. Germer, E. Gevorgyan, F. Haule, Harry Hoffmann, F.C. Kahimba, L. Kashaga, L. Kissoly, C. Lambert, M. Lana, H.F. Mahoo, B. Makoko, S.H. Mbaga, A. Mmbughu, S. Mkangwa, L. Mrosso, K.D. Mutabazi, L. Mwinuka, H. Ngazi, E. Nkonya, C. Reif, S. Said, A. Schaffert, M.P. Schäfer, J. Schindler, S. Sieber, M. Swamila, H.M. Welp, L. William, Y.M. Yustas. Natural Resource Management and Crop Production Strategies to Improve Regional Food Systems in Tanzania. Outlook on Agriculture. 2015; 44 (2):159-167.

Chicago/Turabian Style

F. Graef; I. Schneider; A. Fasse; J.U. Germer; E. Gevorgyan; F. Haule; Harry Hoffmann; F.C. Kahimba; L. Kashaga; L. Kissoly; C. Lambert; M. Lana; H.F. Mahoo; B. Makoko; S.H. Mbaga; A. Mmbughu; S. Mkangwa; L. Mrosso; K.D. Mutabazi; L. Mwinuka; H. Ngazi; E. Nkonya; C. Reif; S. Said; A. Schaffert; M.P. Schäfer; J. Schindler; S. Sieber; M. Swamila; H.M. Welp; L. William; Y.M. Yustas. 2015. "Natural Resource Management and Crop Production Strategies to Improve Regional Food Systems in Tanzania." Outlook on Agriculture 44, no. 2: 159-167.

Review article
Published: 31 January 2014 in Global Food Security
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Enhancing food security for poor and vulnerable people requires adapting rural food systems to various driving factors. Food security-related research should apply participatory action research that considers the entire food value chain to ensure sustained success. This article presents a research framework that focusses on determining, prioritising, testing, adapting and disseminating food securing upgrading strategies across the multiple components of rural food value chains. These include natural resources, food production, processing, markets, consumption and waste management. Scientists and policy makers jointly use tools developed for assessing potentials for enhancing regional food security at multiple spatial and temporal scales. The research is being conducted in Tanzania as a case study for Sub-Saharan countries and is done in close collaboration with local, regional and national stakeholders, encompassing all activities across all different food sectors.

ACS Style

F. Graef; S. Sieber; K. Mutabazi; Folkard Asch; H.K. Biesalski; J. Bitegeko; W. Bokelmann; M. Bruentrup; O. Dietrich; N. Elly; A. Fasse; J.U. Germer; U. Grote; L. Herrmann; Harry Hoffmann; F.C. Kahimba; B. Kaufmann; Kurt Christian Kersebaum; C. Kilembe; A. Kimaro; J. Kinabo; B. König; Hannes J. König; M. Lana; C. Levy; J. Lyimo-Macha; B. Makoko; G. Mazoko; S.H. Mbaga; W. Mbogoro; H. Milling; K. Mtambo; Klaus Mueller; E. Nkonja; C. Reif; C. Ringler; S. Ruvuga; M. Schaefer; A. Sikira; V. Silayo; K. Stahr; E. Swai; S. Tumbo; Götz Bernhard Uckert. Framework for participatory food security research in rural food value chains. Global Food Security 2014, 3, 8 -15.

AMA Style

F. Graef, S. Sieber, K. Mutabazi, Folkard Asch, H.K. Biesalski, J. Bitegeko, W. Bokelmann, M. Bruentrup, O. Dietrich, N. Elly, A. Fasse, J.U. Germer, U. Grote, L. Herrmann, Harry Hoffmann, F.C. Kahimba, B. Kaufmann, Kurt Christian Kersebaum, C. Kilembe, A. Kimaro, J. Kinabo, B. König, Hannes J. König, M. Lana, C. Levy, J. Lyimo-Macha, B. Makoko, G. Mazoko, S.H. Mbaga, W. Mbogoro, H. Milling, K. Mtambo, Klaus Mueller, E. Nkonja, C. Reif, C. Ringler, S. Ruvuga, M. Schaefer, A. Sikira, V. Silayo, K. Stahr, E. Swai, S. Tumbo, Götz Bernhard Uckert. Framework for participatory food security research in rural food value chains. Global Food Security. 2014; 3 (1):8-15.

Chicago/Turabian Style

F. Graef; S. Sieber; K. Mutabazi; Folkard Asch; H.K. Biesalski; J. Bitegeko; W. Bokelmann; M. Bruentrup; O. Dietrich; N. Elly; A. Fasse; J.U. Germer; U. Grote; L. Herrmann; Harry Hoffmann; F.C. Kahimba; B. Kaufmann; Kurt Christian Kersebaum; C. Kilembe; A. Kimaro; J. Kinabo; B. König; Hannes J. König; M. Lana; C. Levy; J. Lyimo-Macha; B. Makoko; G. Mazoko; S.H. Mbaga; W. Mbogoro; H. Milling; K. Mtambo; Klaus Mueller; E. Nkonja; C. Reif; C. Ringler; S. Ruvuga; M. Schaefer; A. Sikira; V. Silayo; K. Stahr; E. Swai; S. Tumbo; Götz Bernhard Uckert. 2014. "Framework for participatory food security research in rural food value chains." Global Food Security 3, no. 1: 8-15.

Journal article
Published: 21 February 2013 in Land Use Policy
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Assessing the impact of macro-level policy driven land use changes on regional sustainability is an important task that can facilitate complex decision making processes of introducing reforms. The research work demonstrates the ability of Sustainability Impact Assessment Tool (SIAT), a meta-model, in conducting ex ante spatially explicit cross sectoral impact assessments of changes in common agricultural policy (CAP). The meta-model is able to appraise impacts of CAP amendments on land use and their repercussions on multiple indicators of sustainability. The presented study comprehensively analyses the possible impacts of discontinuing direct financial support to farmers under CAP. The simulations of the meta-model are able to reveal the land use changes both at EU and regional levels as well as to bring forth the subsequent changes in a number of indicators representing the regional sustainability (for five case study regions). In a nutshell, the simulations indicate that a reduction in direct support brings in general, a decrease in farmed area, an increase in forested land, less fluctuation in natural vegetation coverage, increase in abandoned arable land area and negligible changes in built-up area despite regionally diverging land use trends. The simulated changes in sustainability indicators for the study regions in consequence to these land use changes show that the discontinuation of subsidies evokes responses that are in general climate friendly (reduction in methane and N2O emissions, diminishing energy use and reduction in global warming potential), economically beneficial (increase in gross value of agriculture) and socially desired (decrease in unemployment rate) as well as environmentally harmful (increase in pesticide use). Even though the appraisals of diversity indicators such as forest deadwood and farmland birds are not conclusive for all regions, the changes are positive for the former indicator and slightly negative for the latter in general. The trade-offs among these regional sustainability indicators using their directional associations are also presented for a comprehensive assessment of the impacts.

ACS Style

S. Sieber; T.S. Amjath-Babu; T. Jansson; K. Müller; K. Tscherning; F. Graef; D. Pohle; K. Helming; B. Rudloff; B.S. Saravia-Matus; S. Gomez Y Paloma. Sustainability impact assessment using integrated meta-modelling: Simulating the reduction of direct support under the EU common agricultural policy (CAP). Land Use Policy 2013, 33, 235 -245.

AMA Style

S. Sieber, T.S. Amjath-Babu, T. Jansson, K. Müller, K. Tscherning, F. Graef, D. Pohle, K. Helming, B. Rudloff, B.S. Saravia-Matus, S. Gomez Y Paloma. Sustainability impact assessment using integrated meta-modelling: Simulating the reduction of direct support under the EU common agricultural policy (CAP). Land Use Policy. 2013; 33 ():235-245.

Chicago/Turabian Style

S. Sieber; T.S. Amjath-Babu; T. Jansson; K. Müller; K. Tscherning; F. Graef; D. Pohle; K. Helming; B. Rudloff; B.S. Saravia-Matus; S. Gomez Y Paloma. 2013. "Sustainability impact assessment using integrated meta-modelling: Simulating the reduction of direct support under the EU common agricultural policy (CAP)." Land Use Policy 33, no. : 235-245.