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    Is sustainable development of semi-subsistence mixed crop-livestock systems possible? : an integrated assessment of Machakos, Kenya
    Valdivia, R.O. - \ 2016
    Wageningen University. Promotor(en): Tammo Bult, co-promotor(en): J. Antle; Jetse Stoorvogel. - Wageningen : Wageningen University - ISBN 9789462578272 - 233
    sustainable development - development economics - livestock - cash crops - agriculture - mixed farming - development policy - policy - rural areas - poverty - farming - kenya - east africa - duurzame ontwikkeling - ontwikkelingseconomie - vee - marktgewassen - landbouw - gemengde landbouw - ontwikkelingsbeleid - beleid - platteland - armoede - landbouw bedrijven - kenya - oost-afrika

    Sub-Saharan Africa countries face the challenge of reducing rural poverty and reversing the declining trends of agricultural productivity and the high levels of soil nutrient depletion. Despite of numerous efforts and investments, high levels of poverty and resource degradation persist in African agriculture. The Millennium Development Goals Report (MDGR) states that the majority of people living below the poverty line of $1.25 a day belong to Sub-Saharan Africa (SSA) and South Asia. About two thirds of the global rural population lives in mixed crop-livestock systems (CLS), typical of SSA, where interactions between crops and livestock activities are important for the subsistence of smallholders. CLS are characterized by high degree of biophysical and economic heterogeneity, complex and diversified production system that frequently involves a combination of several subsistence and cash crops and livestock. Increasing crop productivity is clearly a key element to improve living standards and to take these people out of poverty. However, agricultural productivity in most of SSA has been stagnant or increased slowly. In addition, the likely negative impacts of climate change on agriculture have accentuated the vulnerability of smallholders.

    The international research community has once more the eyes on SSA with the recently proposed post-2015 MDGs, the Sustainable Development Goals that emphasize the need to achieve sustainable development globally by 2030 by promoting economic development, environmental sustainability, good governance and social inclusion. Governments and scientists are making considerable efforts to develop strategies that include structural transformations of the different sectors of the economy in search of the recipe to achieve the SDGs. Most of these strategies are based on policy and technology interventions that seek to achieve the “win-win” outcomes and move from the usual “tradeoffs” between poverty-productivity-sustainability to synergies. A key message of this thesis is that achieving the goal of sustainable development in semi-subsistence African agriculture will require better understanding of the poverty-productivity-sustainability puzzle: why high poverty and resource degradation levels persist in African agriculture. I hypothesize that the answer to this puzzle lies, at least in part, in understanding and appropriately analyzing key features of semi-subsistence crop-livestock systems (CLS) typical of Sub-Saharan Africa. The complexity and diversity of CLS often constrain the ability of policy or technology interventions to achieve a “win-win” outcome of simultaneously reducing poverty while increasing productivity sustainably (i.e., avoiding soil nutrient losses).

    This thesis focuses on the Machakos Region in Kenya. Machakos has been the center of many studies looking at soil fertility issues and its implications for poverty and food security, including the well-known study by Tiffen et al. (1994). Recently, the Government of Kenya developed the Kenya Vision 2030, a long-term development strategy designed to guide the country to meet the 2015 MDGs and beyond. The agricultural sector is recognized as one of the economic actors that can lead to reduce poverty if appropriate policies are in place. For the Vision 2030, the key is to improve smallholder productivity and promote non-farm opportunities. The Vision 2030 was used to assess if the implementation of some of the proposed plans and policies can lead to a sustainable agriculture for smallholders in the Machakos region.

    This thesis describes and uses the Tradeoff Analysis Model (TOA), an integrated modeling approach designed to deal with the complexities associated to production systems such as the CLS and at the same time, quantify economic and sustainability indicators for policy tradeoff analysis (e.g., poverty indexes and measures of sustainability). The TOA was linked to Representative Agricultural Pathways and Scenarios to represent different future socio-economic scenarios (based on the Vision 2030) to assess the impacts of policy interventions aimed to move agricultural systems towards meeting sustainable development goals.

    One important finding is that the complex behavior of CLS has important implications for the effectiveness of policy interventions. The Machakos analysis provides important findings regarding the implementation and effectiveness of policy interventions addressing poverty and sustainability in Africa and other parts of the developing world. The analysis shows that policy interventions tend to result in much larger benefits for better-endowed farms, implying that farm heterogeneity results in differential policy impacts and that resilience of agricultural systems is likely to be highly variable and strongly associated with heterogeneity in bio-physical and economic conditions. The results shows that a combination of these interventions and strategies, based on the GoK Vision 2030 and the Machakos County plans, could solve the poverty-productivity-sustainability puzzle in this region. The pathway from tradeoffs to synergies (win-win) seems to be feasible if these interventions and strategies are well implemented, however the analysis also shows that some villages may respond better to these strategies than others. The analysis suggests that these interventions may actually benefit most the areas with better initial endowments of soils and climate.

    The analysis also suggested that prices (e.g., maize price) play a key role in the assessment of policy interventions. There is an increasing recognition that analysis of economic and environmental outcomes of agricultural production systems requires a bottom-up linkage from the farm to market, as well as top-down linkage from market to farm. Hence, a two-way linkage between the TOA model and a partial equilibrium market model (ME) was developed. The TOA model links site-specific bio-physical process models and economic decision models, and aggregate economic and environmental outcomes to a regional scale, but treats prices as exogenous. The resulting TOA-ME allows the effects of site-specific interactions at the farm scale to be aggregated and used to determine market equilibrium. This in turn, can be linked back to the underlying spatial distribution of economic and environmental outcomes at market equilibrium quantities and prices. The results suggest that market equilibrium is likely to be important in the analysis of agricultural systems in developing countries where product and input markets are not well integrated, and therefore, local supply determines local prices (e.g., high transport costs may cause farm-gate prices be set locally) or where market supply schedules are driven not only by prices but also by changes in farm characteristics in response to policy changes, environmental conditions or socio-economic conditions. The results suggest that the market equilibrium price associated to a policy intervention could be substantially different than the prices observed without the market equilibrium analysis, and consequently could play an important role in evaluating the impacts of policy or technology interventions.

    As mentioned above, climate change poses a long-term threat for rural households in vulnerable regions like Sub-Saharan Africa. Policy and technology interventions can have different impacts under climate change conditions. In this thesis the likely economic and environmental impacts of climate change and adaptations on the agricultural production systems of Machakos are analyzed.

    Climate change impact assessment studies have moved towards the use of more integrated approaches and the use of scenarios to deal with the uncertainty of future condition. However, several studies fall short of adequately incorporating adaptation in the analysis, they also fall short of adequately assessing distributional economic and environmental impacts. Similarly, climate change is likely to change patterns of supply and demand of commodities with a consequent change in prices that could play an important role in designing policies at regional, national and international levels. Therefore, a market equilibrium model should also be incorporated in the analysis to assess how markets react to changing prices due to shifts in supply and demand of commodities. The TOA-ME was used to incorporate the elements mentioned above to assess the impacts of climate change. Using data from 5 Global Circulation Models (GCMs) with three emission scenarios (SRES, 2000) to estimate the climate change projections, these projections were used to perturb weather data used by a crop simulation model to estimate the productivity effects of climate change. Land use change and impacts on poverty and nutrient depletion at the market equilibrium were then assessed using the TOA-ME model.

    The simulation was carried out for three scenarios, which are a combination of socio-economic and climate change scenarios: a baseline scenario that represents current socio-economic conditions and climate conditions, a climate change and current socio-economic scenarios (i.e., future climate change with no policy or technology intervention), and a climate change and future socio economic conditions which are a consequence of rural development policies.

    Our findings show that in this particular case, the changes on precipitation, temperature and solar radiation do not show a significant difference among the selected emission scenarios. However, the variability is significant across GCMs. The effects of climate change on crop productivity are negative on average. These results show that policy and technology interventions are needed to reduce this region’s vulnerability. Furthermore, the socio-economic scenarios based on policy and technology interventions presented in the case study would be effective to offset the negative effect of climate change on the sustainability (economical and environmental) of the system across a range of possible climate outcomes represented by different GCMs. Finally, the results show that ignoring market equilibrium analysis can lead to biased results and incorrect information for policy making, in particular for the scenario based on policy and technology interventions.

    One of the major conclusions of the thesis are that policy interventions aimed to deal with poverty and sustainability can have unintended consequences if they are not accompanied by a set of policy strategies and investments. For example, increasing the maize price can result in substitution from subsistence crops to maize, without much increase in nutrient inputs, thus increasing soil nutrient losses. The analysis shows that improving soil nutrient balances by increasing fertilizer and manure use is critically important, but is not enough to move the system to a sustainable path.

    There is no one factor that can reverse the negative nutrient balances and move the system towards sustainability. Rather, a broad-based strategy is required that stimulates rural development, increases farm size to a sustainable level, and also reduces distortions and inefficiencies in input and output markets that tend to discourage the use of sustainable practices. The Machakos case shows that a combination of these interventions and strategies, based on the GoK Vision 2030 and the Machakos County plans, could solve the poverty-productivity-sustainability puzzle in this region.

    Crop-Livestock Intensification in the Face of Climate Change: Exploring Opportunities to Reduce Risk and Increase Resilience in Southern Africa Using an Integrated Multi-Modeling Approach
    Masikati, P. ; Homann-Kee Tui, S. ; Descheemaeker, K. ; Crespo, O. ; Walker, S. ; Lennard, C.J. ; Claessens, L.F.G. ; Gama, A.C. ; Famba, S. ; Rooyen, A.F. van; Valdivia, R.O. - \ 2015
    In: Handbook of Climate and Agroecosystems / Rosenzweig, Cynthia, Hillel, Daniel, World Scientific Publishing (ICP Series on Climate Change Impacts, Adaptation, and Mitigation ) - ISBN 9781783265633 - p. 159 - 198.
    Scoping climate change adaptation strategies for smallholder farmers in East Africa - a multi-dimensional, multi-scenario impact assessment
    Claessens, L.F.G. ; Antle, J.M. ; Stoorvogel, J.J. ; Valdivia, R.O. ; Thornton, P.K. ; Herrero, M. - \ 2015
    In: Climate change challenges and adaptations at farm-level: case studies from Asia and Africa / Singh, N.P., Bantilan, C., Byjesh, K., Nedumaran, S., CABI (CABI Climate Change Series ) - ISBN 9781780644639 - p. 138 - 145.
    This chapter assesses the characteristics of current and future agricultural systems, land use, agricultural output, output price, cost of production, and farm and household size in response to climate change. This analysis also compared both current and projected future climate (2030), with and without adaptation, and for different socioeconomic scenarios (Representative Agricultural Pathways, RAPs) in two study areas in Kenya. A new approach to impact assessment, the Tradeoff Analysis Model for Multi-Dimensional Impact Assessment (TOA-MD) was adopted for this analysis, which simulated technology adoption and associated economic, environmental and social outcomes in a heterogeneous farm population for a regional impact assessment. These case studies yield new insights into the way that adaptation strategies could improve the livelihoods of smallholder farmers operating in the mixed crop-livestock systems in East Africa.
    New parsimonious simulation methods and tools to assess future food and environmental security of farm populations.
    Antle, J.M. ; Stoorvogel, J.J. ; Valdivia, R.O. - \ 2014
    Philosophical Transactions of the Royal Society B. Biological sciences 369 (2014)1639. - ISSN 0962-8436
    agricultural production systems - tradeoff analysis model - soil nutrient balances - climate-change - ecosystem services - policies - impact - level - scale - kenya
    This article presents conceptual and empirical foundations for new parsimonious simulation models that are being used to assess future food and environmental security of farm populations. The conceptual framework integrates key features of the biophysical and economic processes on which the farming systems are based. The approach represents a methodological advance by coupling important behavioural processes, for example, self-selection in adaptive responses to technological and environmental change, with aggregate processes, such as changes in market supply and demand conditions or environmental conditions as climate. Suitable biophysical and economic data are a critical limiting factor in modelling these complex systems, particularly for the characterization of out-of-sample counterfactuals in ex ante analyses. Parsimonious, population-based simulation methods are described that exploit available observational, experimental, modelled and expert data. The analysis makes use of a new scenario design concept called representative agricultural pathways. A case study illustrates how these methods can be used to assess food and environmental security. The concluding section addresses generalizations of parametric forms and linkages of regional models to global models.
    Economic and Environmental Impacts of Climate Change and Socio-economic Scenarios: A Case Study on a Semi-subsistence Agricultural Production System
    Valdivia, R.O. ; Stoorvogel, J.J. ; Antle, J.M. - \ 2012
    The International Journal of Climate Change: Impacts and Responses 3 (2012)2. - ISSN 1835-7156 - p. 157 - 176.
    In this study we use a spatially-explicit integrated assessment model (TOA-ME) to evaluate the economic (income, poverty) and environmental (soil nutrient depletion) impacts of climate change and socio-economic scenarios in a case study of the semi-subsistence agricultural production systems of Machakos (Kenya). This model provides a unique capability to assess distributional effects of climate change on economic and environmental outcomes while also accounting for market-level impacts on prices. We use this framework to examine how a socio-economic scenario based on policy and technology interventions can offset the likely negative effects of climate change. In order to conduct this analysis we propose a three-step methodology: i) analysis of climate change scenarios generated by GCMs, ii) use of GCMs output to estimate crop responses, and iii) modeling the land use decisions and economics of the farming systems. Output data from 5 commonly used GCMs and 3 emission scenarios were used. Outputs from GCMs and emission scenarios corresponding to the Machakos region are highly variable but present a similar trend of higher temperatures and decreasing precipitation. As a result, crop production decreases with the effects varying by location. Farmers are likely to adapt to the new climate conditions through changes in land use; however the effects on poverty and soil nutrient depletion rates are small. In contrast, the analysis shows that an effective policy and technology intervention that leads to different socio-economic conditions could offset the negative effects of climate change and reduce this region’s vulnerability. The results also imply that ignoring new market conditions could lead to incorrect information for policy making.
    Coupling the Tradeoff Analysis Model with a market equilibrium model to analyze economic and environmental outcomes of agricultural production systems.July 2012
    Valdivia, R.O. ; Antle, J.M. ; Stoorvogel, J.J. - \ 2012
    Agricultural Systems 110 (2012). - ISSN 0308-521X - p. 17 - 29.
    integrated assessment - ecosystem services - policies - impacts
    Analysis of the economic and environmental outcomes of agricultural systems requires a bottom-up linkage from the farm to market, as well as a top-down linkage from market to farm. This study develops this two-way linkage between the Tradeoff Analysis Model of agricultural systems and a partial equilibrium market model. The resulting model can determine the effects of technology and policy interventions on the spatial distribution of environmental and economic outcomes at market equilibrium quantities and prices. The approach is demonstrated with a case study of tradeoffs between poverty and nutrient depletion in a semi-subsistence agricultural system (Machakos, Kenya). The results suggest that the linkage of market equilibrium analysis to farm level Integrated Assessment Models can be important in the analysis of agriculture–environment interactions.
    A method for evaluating climate change adaptation strategies for small-scale farmers using survey, experimental and modeled data
    Claessens, L.F.G. ; Antle, J.M. ; Stoorvogel, J.J. ; Valdivia, R.O. ; Thornton, P.K. ; Herrero, M. - \ 2012
    Agricultural Systems 111 (2012). - ISSN 0308-521X - p. 85 - 95.
    ecosystem services - developing-countries - technology adoption - western kenya - crop yield - impacts - systems - africa - sustainability - agriculture
    Sub-Saharan Africa (SSA) is predicted to experience considerable negative impacts of climate change. The IPCC Fourth Assessment emphasizes that adaptation strategies are essential. Addressing adaptation in thecontext of small-scale, semi-subsistence agriculture raises special challenges. High data demands includingsite-specific bio-physical and economic data are an important constraint. This paper applies a newapproach to impact assessment, the Tradeoff Analysis model for Multi-Dimensional Impact Assessment(TOA-MD), which simulates technology adoption and associated economic, environmental and social outcomes in a heterogeneous farm population for a regional impact assessment. The methodology uses thekinds of survey, experimental and modeled data that are typically available in countries where semi-subsistencesystems are important, combined with future socio-economic scenarios based on new scenario pathway concepts being developed by the climate change and impact assessment modeling communities. Characteristics of current and future agricultural systems, including land use, output, output price, cost of production, and farm and household size are analyzed and compared for both current and projected future climate (2030), with and without adaptation, and for different socio-economic scenarios. The methodology is applied to two study areas in Kenya. These case studies show the potential of this approach to provide a flexible, generic framework that can use available and modeled data to evaluate climate impact and adaptation strategies under a range of socio-economic scenarios.
    Minimum-data analysis of ecosystem service supply in semi-subsistence agricultural systems
    Antle, J.M. ; Diagana, B. ; Stoorvogel, J.J. ; Valdivia, R.O. - \ 2010
    The Australian Journal of Agricultural and Resource Economics 54 (2010)4. - ISSN 1364-985X - p. 601 - 617.
    carbon sequestration - kenya - sustainability - efficiency - payments - policies - design - model
    Antle and Valdivia (2006, Australian Journal of Agricultural and Resource Economics 50, 1–15) proposed a minimum-data (MD) approach to simulate ecosystem service supply curves that can be implemented using readily available secondary data and validated the approach in a case study of soil carbon sequestration in a monoculture wheat system. However, many applications of the MD approach are in developing countries where semi-subsistence systems with multiple production activities are being used and data availability is limited. This paper discusses how MD analysis can be applied to more complex production systems such as semi-subsistence systems with multiple production activities and presents validation analysis for studies of soil carbon sequestration in semi-subsistence farming systems in Kenya and Senegal. Results from these two studies confirm that ecosystem service supply curves based on the MD approach are close approximations to the curves derived from highly detailed data and models and are therefore sufficiently accurate and robust to be used to support policy decision making
    Ex ante assessment of climate change adaptation strategies in resource-poor countries: study cases from East Africa
    Claessens, L. ; Stoorvogel, J.J. ; Antle, J.M. ; Valdivia, R.O. ; Thornton, P.K. ; Herrero, M. - \ 2009
    Coupling integrated assessment models to market equilibrium models to analyse economic and agricultural-environmental interactions across different scales
    Valdivia, R.O. ; Antle, J.M. ; Stoorvogel, J.J. - \ 2009
    In: Proceedings of the Conference on Integrated Assessment of Agriculture and Sustainable Development; Setting the Agenda for Science and Policy (AgSAP 2009), Egmond aan Zee, The Netherlands, 10-12 March 2009. - Wageningen, The Netherlands : Wageningen University and Research Centre - ISBN 9789085854012 - p. 68 - 69.
    A minimum-data approach to ex-ante assessment of climate change adaptation strategies in resource-poor countries
    Claessens, L. ; Stoorvogel, J.J. ; Antle, J.M. ; Valdivia, R.O. ; Herrero, M. - \ 2009
    In: Proceedings of the Conference on Integrated Assessment of Agriculture and Sustainable Development; Setting the Agenda for Science and Policy (AgSAP 2009), Egmond aan Zee, The Netherlands, 10-12 March 2009. - Wageningen, The Netherlands : Wageningen University and Research Centre - ISBN 9789085854012 - p. 408 - 409.
    Assessing poverty-sustainability trade-offs in semi-subsistence agricultural systems: A case study of policy options in Machakos, Kenya
    Antle, J.M. ; Stoorvogel, J.J. ; Valdivia, R.O. - \ 2009
    In: Proceedings of the Conference on Integrated Assessment of Agriculture and Sustainable Development; Setting the Agenda for Science and Policy (AgSAP 2009), Egmond aan Zee, The Netherlands, 10-12 March 2009. - Wageningen, The Netherlands : Wageningen University and Research Centre - ISBN 9789085854012 - p. 472 - 473.
    The Trade-off Analysis software: Modelling tools to support informed policy decision making
    Antle, J.M. ; Stoorvogel, J.J. ; Valdivia, R.O. - \ 2009
    In: Proceedings of the Conference on Integrated Assessment of Agriculture and Sustainable Development; Setting the Agenda for Science and Policy (AgSAP 2009), Egmond aan Zee, The Netherlands, 10-12 March 2009. - Wageningen, The Netherlands : Wageningen University and Research Centre - ISBN 9789085854012 - p. 318 - 319.
    Assessing the economic impacts of agricultural carbon sequestration: Terraces and agroforestry in the Peruvian Andes
    Antle, J.M. ; Stoorvogel, J.J. ; Valdivia, R.O. - \ 2007
    Agriculture, Ecosystems and Environment 122 (2007)4. - ISSN 0167-8809 - p. 435 - 445.
    production systems - senegal - region - design - models - costs
    There is an increasing demand for information about the economic impact of agricultural carbon (C) sequestration in the developing world, but as yet no studies have assessed the potential for farmers in the highland tropics to participate in C contracts. In this paper we show how an econometric-process simulation model, designed to simulate the value of terrace and agroforestry investments, can be used to assess the economic feasibility of C sequestration. We use this model to simulate the impact of C contracts on the adoption of terraces and agroforestry practices in the highlands of northern Peru. The analysis shows that participation in C contracts could increase adoption of terraces and agroforestry practices, with the rate of adoption depending on the C accumulation rate and key factors affecting terrace productivity such as field slope. The simulation results show there is a relatively low economic potential for C sequestration in this agricultural system at C prices below $50 per MgC, but that potential increases substantially for C prices above $50 per MgC. Under favorable conditions for C sequestration and a C price of $100 per MgC, terrace and agroforesty adoption and C sequestration have the potential to raise per capita incomes by up to 15% on farms with steeply sloped fields, and reduce poverty by as much as 9%.
    Multiple equilibria, soil conservation investments and the resilience of agricultural systems
    Antle, J.M. ; Stoorvogel, J.J. ; Valdivia, R.O. - \ 2006
    Environment and Development Economics 11 (2006)4. - ISSN 1355-770X - p. 477 - 492.
    fertility management - irreversibility - productivity - africa - kenya
    This paper provides a new explanation for the persistent land degradation in some parts of the world, despite the availability of seemingly effective soil conservation technologies.We demonstrate that soil conservation technologies may induce agricultural systems to exhibit equilibria characterized by both low and high levels of soil degradation. These two equilibria are separated by a threshold level of soil degradation beyond which a conservation investment will not yield a positive return. Once a parcel of land crosses this productivity threshold, soil degradation becomes economically irreversible (it is not profitable to invest in soil conservation) even though the degradation may be technically reversible. A case study of terracing investments in Peru is used to demonstrate the existence of multiple equilibria under conditions typical of many marginal agricultural areas. These findings help explainwhy attempts to encourage permanent adoption of soil conservation practices often fail, and how more successful policies could be designed.
    Spatial heterogeneity and adoption of soil conservation investments: integrated assessment of slow formation terraces in the andes
    Antle, J.M. ; Valdivia, R.O. ; Crissman, C.C. ; Stoorvogel, J.J. ; Yanggen, D. - \ 2005
    Journal of International Agricultural Trade and Development 1 (2005)1. - ISSN 1556-8520 - p. 29 - 53.
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