GEOSTATISTICAL ANALYSIS OF SOIL PROPERTIES OF THE KARSTIC SUB-HORIZONTAL PLAIN OF THE YUCATAN PENINSULA

Abstract

Background: In recently formed karst environments, as in the north of the state of Yucatan, Mexico, many chemical and physical properties of soils have a high spatial heterogeneity. However, this heterogeneity of the soil is not well-understood, which affects the agricultural use of the land. Objective: To identify the soil properties that best allow zoning, in order to select them for precision agriculture. Methodology: A plot was divided into 54 quadrants of 25 m2 (5 x 5 m). In each quadrant, the properties of the soil described or analyzed were the stoniness, rockiness, depth, silt, sand, clay, particle density, bulk density, organic carbon, and field capacity. A georeferenced database of soil properties was built. Geostatistical analyzes were performed using ordinary kriging (parametric) and indicator kriging (probabilistic) interpolations. The precision of the interpolations was estimated. The soil property maps were constructed in Arc GIS. Results: The organic carbon, bulk density, rockiness, particle density, stoniness, silt, and sand were the soil properties with the best adjustment values between the theoretical and experimental models. In addition, those same soil properties had good, high, and very high correlations between data measured and data estimated with the interpolation. On the other hand, the depth, clay, and field capacity were the properties of soils with adjustment values lower than r2 = 0.8, as well as with cross-validation values of less than r = 0.5. Implications: The probabilistic maps of soil depth allowed us to identify the areas with Nudilithic, Lithic, and other Leptosols. Conclusion: The percentage of organic matter and depth represent the two soil properties that could be best applied to conduct parcel zoning for the sake of achieving better precision agriculture.