A robust method for estimating soil properties in unsampled cells

For site-specific crop management (SSCM), fields are viewed as collections of small regions (cells) in which soil properties are nearly uniform. A field information system (FIS) can be used to store soil fertility data and to create application rate maps on a cell-by-cell basis. A data blocking procedure was developed to convert soil sample data into a new data set in which one value represents the soil property in each cell. A nonparametric distance-weighting algorithm was developed which produced about the same estimation errors as a kriging method, but was much faster. Example applications of the data blocking procedure to KC1 extractable nitrate and soil organic matter data are included.