Abstract
Simple computational methods are presented which facilitate fitting regression models to response data exhibiting a plateau effect. The iterative statistical program (called PLATFOR) is written in FORTRAN (a SAS version is also available), and produces all relevant regression statistics, plots, and information on goodness of fit. The presented procedures are empirically valuable, since linear-plateau models have many useful applications in agriculture, especially in soil fertility and soil chemistry experiments. The technique was employed in an experiment designed to determine the effect of soil volcanic ash content on selenite adsorption. Ion chromatographic methods were used to investigate selenite adsorption in three acidic North Idaho surface soils of varying ash content. Equilibration periods of 0.5 to 12.0 hours were evaluated and the time required to reach maximum adsorption was determined using the PLATFOR program. It was concluded that both the rate and magnitude of selenite adsorption were influenced by soil volcanic ash content.
Keywords
linear-plateau models, regression analysis, selenite adsorption
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Recommended Citation
Shafii, Bahman; Harper, Kevin C.; and McGeehan, Steven L.
(1990).
"LINEAR-PLATEAU REGRESSION ANALYSIS AND ITS APPLICATION TO SELENITE ADSORPTION RATE,"
Conference on Applied Statistics in Agriculture.
https://doi.org/10.4148/2475-7772.1437
LINEAR-PLATEAU REGRESSION ANALYSIS AND ITS APPLICATION TO SELENITE ADSORPTION RATE
Simple computational methods are presented which facilitate fitting regression models to response data exhibiting a plateau effect. The iterative statistical program (called PLATFOR) is written in FORTRAN (a SAS version is also available), and produces all relevant regression statistics, plots, and information on goodness of fit. The presented procedures are empirically valuable, since linear-plateau models have many useful applications in agriculture, especially in soil fertility and soil chemistry experiments. The technique was employed in an experiment designed to determine the effect of soil volcanic ash content on selenite adsorption. Ion chromatographic methods were used to investigate selenite adsorption in three acidic North Idaho surface soils of varying ash content. Equilibration periods of 0.5 to 12.0 hours were evaluated and the time required to reach maximum adsorption was determined using the PLATFOR program. It was concluded that both the rate and magnitude of selenite adsorption were influenced by soil volcanic ash content.
