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Soil degradation in China: implications for agricultural sustainability, food security and the environment

Date

2012

Authors

Hou, Lingling, author
Hoag, Dana L. K., advisor
Loomis, John B., committee member
Davies, Stephen P., committee member
Arabi, Mazdak, committee member

Journal Title

Journal ISSN

Volume Title

Abstract

This dissertation consists of one introduction chapter and three essays, which describe and discuss methods to address three separate but related issues in soil management in China. In my introductory Chapter, I discuss the background for the soil degradation in China and how soil degradation threatens food security, the environment and agricultural sustainability. In the first essay in Chapter 2, I develop a dynamic optimization model for soil management and provide implications for the influence of externalities on intertemporal management of soil capital. This chapter contributes to the literature by providing a more comprehensive dynamic optimization model from a social planner's standpoint, who is concerned about agricultural sustainability, environmental quality and food security. A comparison by numerical methods between a public model and a private model implies that optimal soil management path is different for farmers than for social planners when externalities are considered. This implies that it is important to take externalities into account when managing natural capital such as soil. Food security, as a positive externality, and environmental pollution, as a negative externality, are complementing each other. Factors affecting farm profits and externalities also affect the optimal path. In Chapter 3, I propose environment-adjusted profit as a more appropriate tool to measure the costs imposed by environmental regulations than abatement costs from a shadow pricing model. Environment-adjusted profit updates abatement costs by taking farmers' mitigation behavior into account. Both abatement costs and environment-adjusted profit are estimated for over 1,700cropping systems in the Loess Plateau of China. Furthermore, a regression was used to determine the cropping systems that are most profitable as environmental regulations were imposed. Results show that conservation techniques and mono-crop corn and rotations such as corn-soybean-corn and alfalfa 3 years-corn-millet contribute more to farm profit if environmental regulations were imposed. The conclusions from this chapter can provide farmers and policy-makers alternative choices to balance both economic and environmental goals, rather than planting all land to trees through the Grain for Green program, which was the choice for many in the Loess Plateau. In Chapter 4, I update the sustainable value approach by a DEA benchmark and apply it to the cropping systems in the Loess Plateau of China to investigate sustainable value and efficiency as measures of sustainability. The cropping systems that contribute the most to sustainability from the perspective of using all types of capital efficiently are identified by a regression model. Sustainable value and efficiency matrices are created to compare the sustainability between any pair of rotations and conservation techniques. Rotations such as CSC, A3CM and FA5MC are most sustainable. Conservation techniques such as terracing, mulching and furrow-ridging are more sustainable. This chapter contributes the literature in soil science by adding economic perspective in analyzing agronomic techniques.

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Subject

agricultural sustainability
China
dynamic optimization model
environment
food security
soil degradation

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