Economic evaluation of crop response to lime
1983
Hall, H.H.
Extract: Optimal input rates for plateau responses such as crop response to lime may be unreliable even though the prediction equation fits the data satisfactorily (as judged by R-squared or residual mean square). Five functions (linear spline, logarithmic, power, quadratic spline, and square root) were fitted to data for alfalfa, corn, and soybeans. All five functions had roughly equal R-squares, but some economic optima, especially from the logarithmic, power, and square-root functions, were sometimes unreasonably large. When treatment levels are equally spaced, the evidence suggests, goodness-of-fit is an unreliable discriminator among alternative response functions.
显示更多 [+] 显示较少 [-]