Is sustainable development of semi-subsistence mixed crop-livestock systems possible? : an integrated assessment of Machakos, Kenya

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.