| This research proposes a method to examine the sustainability of resource management. For a unique production input, the endowment of a natural resource may be modeled as an index of quality consisting of the most important characteristics of the resource. It may be placed into a production setting where under different definitions of sustainability, the economic, social and environmental impacts of input management may be compared. The management decisions can also be evaluated with respect to substitution, reversibility, and uncertainty criteria.;Three general soil types---stable, neutral and susceptible--were selected for the study. Available water capacity, bulk density, organic matter, pH and rooting depth were integrated into an index that provided a floating evaluation of soil quality. This index was used in a corn production setting to address three questions: (1) Do US soil conservation policies meet sustainability objectives? (2) What are the impacts of different definitions of sustainability on the economy and the environment? (3) How do substitution, reversibility and uncertainty affect optimal soil management?;The answers to these questions were dependent upon soil type. For stable soils, soil conservation policies met sustainability objectives; the definitions of sustainability were compatible; these definitions were all met with the same management policy which produced high profit and annual yields, a steady input use and low leaching; substitution among inputs existed, reversibility was possible and therefore uncertainties such as input price shocks proposed little threat. However, the less stable the soil, the more likely that soil conservation would fall short of sustainability objectives; that the definitions of sustainability would become incompatible and even unattainable; that the resulting impacts will be more negative than for stable soils; that inputs would become complementary, reversibility impossible and therefore uncertainties might be of great concern.;Although these results may be contingent upon assumptions of this research, it is expected that the general concepts will hold across all soils and crops. Moreover, these concepts may serve as a guide for addressing more complex issues such as concurrent management of multiple natural resources. |
