Gwathmey, C. Owen

By: Harmon, Xavier; Boyer, Christopher N.; Lambert, Dayton M.; Larson, James A.; Gwathmey, C. Owen
We determined the value of soil test information for potassium (K) in upland cotton production using the linear response plateau (LRP) and linear response stochastic plateau (LRSP) functions. A stochastic dynamic programming model was used to determine the net present value to K fertilizer when optimal K was applied with knowledge about K carryover. Using K carryover information for K application decisions increased net present value and helped maintain steady levels of soil K. The LRSP function fit the data better than the LRP, and the value of soil testing was $27 ha-1 lower over ten years using the LRSP.
By: Larson, James A.; Roberts, Roland K.; Gwathmey, C. Owen
Farmers are concerned about the high cost of planting herbicide-resistant cotton with the high plant densities recommended for ultra-narrow-row cotton. This study evaluated the effects on net revenues of four herbicide-resistant technology fee policies used since 1996 by Monsanto, the technology license holder. Results indicate that changes in the technology fee policy by Monsanto have raised the cost of planting herbicide-resistant cotton. As a consequence, farmers may have an incentive to switch from ultra-narrow-row cotton to wide-row cotton and to use a lower plant density when the technology fee is tied to the seeding rate.