| dc.description.abstracteng | Poverty and food insecurity are key global challenges. In the history of agriculture, advances in technology have contributed to increased food supply. Particularly, the green revolution has brought remarkable productivity growth in developing countries. Over the last six decades, the productivity of staple crops – such as maize, rice and wheat – has more than doubled. This in turn has increased food supply, calorie availability, and lowered food and feed prices. However, the green revolution was not sustainable because of the accompanying environmental problems that caused soil and water pollution, loss of biodiversity, greenhouse gas emissions and eventually human health problems. Since the green revolution targeted irrigated and high potential areas, many poor people living in marginal areas were also left behind.
Additional growth in agricultural productivity is required to reduce poverty, food and nutrition insecurity, and to meet the future demand for agricultural products. Goal two of the UN Sustainable Development Goals targets doubling productivity between 2015 and 2030 through sustainable agricultural intensification. Sustainable intensification necessitates the use of technologies and practices that increase productivity while enhancing resilience of farmers and their farming systems to climate change. Being promoted as climate-smart agriculture, the technologies and practices should enable maintaining healthy soils for crop nutrition, promoting biodiversity, containing diseases, pests and weeds, and improving efficiency of water use, and they are often context specific. Many empirical studies have attempted to identify appropriate technologies and practices for various farming systems. In this dissertation, we contribute to this body of literature by analyzing the productivity, efficiency, and risk implications of farmers’ tillage and seed choice practices. The analysis builds on two representative panel household datasets from the small farm sector in Ethiopia. The dissertation consists of three essays addressing distinct research objectives.
Conservation agriculture in general and reduced tillage in particular is gaining attention as one component of climate-smart agriculture. However, farmers in many developing countries still practice intensive tillage since reduced tillage is largely unknown to them. The economic implications of intensive tillage practices are not yet sufficiently studied even though this is crucial for designing sustainable tillage policy and promotion of conservation agriculture. In Essay 1, we analyze the impact of farmers’ intensive tillage practices on wheat productivity and farmers’ risk exposure. To the best of our knowledge, this research is the first that documents the impact of intensive tillage practices on farmers’ risk exposure in developing countries. Furthermore, previous studies on conservation agriculture treat non-adopters of reduced tillage as a homogeneous group. Nevertheless, farmers who practice intensive tillage are more likely to be heterogeneous. Our data provide us with an opportunity to understand the heterogeneous effects of various intensities of tillage. In order to control for selection bias associated with the choice of intensity of tillage, we estimate a flexible moment-based production function using an endogenous switching regression treatment effects model. We find that higher intensities of tillage are associated with higher productivity than lower intensities of tillage. Our findings also show that exposure to risk is lower in higher intensities of tillage and that the estimated risk premium, which is the amount risk averse farmers are willing to pay to avoid risk, is the lowest at higher intensities of tillage. We conclude that farmers use tillage as a strategy to increase productivity and minimize production risks. This suggests that the opportunity costs of switching to reduced tillage are rather high unless farmers are supported by appropriate incentive schemes.
Reducing production losses associated with crop diseases is one of the key objectives of climate-smart agriculture, and rust diseases are one of the major wheat production threats worldwide. The importance of breeding for disease resistance using locally adapted and preferred germplasms are well understood in theory. However, the performance of improved disease resistant varieties in farmers’ fields has rarely been quantified. While the productivity effects of improved varieties are well studied, most studies do not distinguish between different varietal traits such as rust resistance traits. In Essay 2, we evaluate the effects of using rust-resistant varieties on wheat productivity. We compare improved varieties that are resistant to stripe rust with improved susceptible and traditional susceptible varieties. Our production function estimates show that improved resistant varieties are more productive than traditional varieties. Furthermore, the productivity gains of improved resistant varieties are higher than improved susceptible varieties. Under drought and other abiotic stresses, our results further show that improved varieties – with and without resistance to yellow rust – performed notably worse than traditional varieties. We observe that breeders were able to successfully combine rust-resistance traits with high yield traits. However, the poor performance of improved varieties during droughts and other stresses may indicate that improved varieties are not well adapted to farmers’ production conditions. The policy implication is that sustainable adoption depends on the success of breeding to not only improve disease resistance and yield traits but also to improve drought tolerance and other production stresses in the same varieties.
Even though high yielding improved varieties provide higher productivity on average, farmers may sub-optimally use improved varieties because they may not always use genetically pure quality seeds of the improved varieties. An important reason for sub-optimal use of improved varieties is the seed recycling practices of farmers in many developing countries. While the impacts of new improved varieties on productivity and efficiency are well documented, the productivity and efficiency effects of fresh and recycled seeds have rarely been studied. In Essay 3, we analyze the impact of using fresh seeds, compared to using recycled seeds from the previous harvest, on both land productivity and efficiency of maize farmers. Given the slow varietal turnover rate and seed recycling practices of farmers in many developing countries, quantifying the benefits of using fresh seeds can help to shed light on how to design strategies of attaining higher productivity in an efficient way without introducing new improved varieties. We estimate random effects production functions in an endogenous switching regression treatment effects model. We find that farmers who used fresh seeds are not only more productive but also more efficient. The observed gains in productivity and efficiency indicate that promoting fresh seeds can potentially contribute to food security. Despite the productivity and efficiency gains, our results further show the presence of significant inefficiency in inputs use. Closing farmers’ inefficiency may need a concerted effort in designing policy instruments that promote input use efficiency.
Overall, the three essays show that farmers’ tillage and seed choice practices are heterogeneous, often varying across plots of the same household. Speeding up widespread adoption of climate-smart agriculture technologies needs to consider these heterogeneous practices and their implications for productivity, efficiency, and production risk. Climate-smart agricultural policies may need to promote modern biotechnology tools for breeding improved varieties responsive to reduced tillage, adapted to the local soil and climatic conditions, and consumption preferences. | de |
| dc.subject.eng | Climate smart agriculture, sustainable agriculture, tillage, agricultural productivity, risk exposure, wheat, Ethiopia, Disease resistance, breeding, wheat rust, yield, technology adoption, Africa, land productivity, efficiency, fresh seeds, seed recycling, maize | de |