Properties of Norfolk and Portsmouth Soils: Statistical Summarization and Influence on Corn Yields
1962
Nelson, L. A. | McCracken, R. J.
Results of chemical, mineralogical, and physical characterizations of 15 profiles each of the Norfolk and Portsmouth soils of the North Carolina Coastal Plain are reported. Purposes of the study were to: (a) determine central tendencies, ranges, and standard deviations of properties; and (b) weight those properties most promising as differentiating criteria for soil classification and characterization. Multiple linear regression techniques were used for this selection and weighting. A mineral index, derived from X-ray diffraction pattern peaks for determining the relative proportions of intergradational vermiculite-chlorite and kaolinite in the surface horizon clay fractions, was found to be a promising differentiating criterion. This is based on its relationship to corn yield response to added nitrogen and “maximum” corn yields (corn yield data were available from another study). Nitrate production was also found to be important in the regression studies. Drouth index and several other factors also occur in the multiple regression models.
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