Tanaka, Donald L.

By: Williams, Jeffery R.; Tanaka, Donald L.; Herbel, Kevin L.
Relationships among topsoil removal treatments and additions of nitrogen and phosphorus fertilizer in spring wheat yields are used to determine the effects on net returns and to estimate the marginal value of soil. The results indicate that risk-averse managers are not willing to make an expenditure for controlling erosion from the first 2.5 inches of soil if the erosion rate is 20 tons/acre/year or less and the planning horizon is 20 years or less. These managers would be willing to make an erosion control investment for the second 2.5 inches of soil equivalent to $4.90 to $5.20/acre from the twenty-first to forty-third year in the planning horizon.