Fertilization Mapping Based on the Soil Properties of Paddy Fields in Korea.

The purpose of this study was to construct a map of expected fertilization rates for nitrogen (N) and phosphorus (P₂O₅) based on measurements of components in soil samples and to identify the spatial variabilities of four lots of a salt-affected paddy field in Korea. Four salt-affected paddy field lots in Korea were divided into 30 sectors for collecting soil samples. They were then analyzed for soil organic matter (SOM), silicon dioxide (SiO₂), total nitrogen (TN), and available phosphorus (Av.P₂O₅) in accordance with international standards. Expected fertilization rates of N and P₂O₅ were developed as prescription standards for the application of fertilizer to paddy fields. They were derived using a model of the fertilization rates of N and P₂O₅. To determine the presence of spatial correlation and continuity in the given fields, a spherical variogram was used. Based on the spherical model with the application of a regular kriging interpolation, maps of the contents of TN and Av.P₂O₅ as well as the expected fertilization rates of N and P₂O₅ at each sector of 1 × 1   m² were developed. The expected fertilization rate of N at each sector appeared in the range of min. 10.0 g to max. 25.7 g, while that of P₂O₅ appeared in the range of min. 0.68 g to max. 8.46 g. [ABSTRACT FROM AUTHOR]