ESTIMATING DEPTHS TO CLAYPANS USING ELECTROMAGNETIC INDUCTION METHODS

Claypans restrict infiltration, influence the lateral movement of soil water and agrichemicals, and limit crop production. In many areas of the Midwest, quantification and mapping of the variations in the depth to claypans are important components for research on water-quality an d crop production. In an area of Mexico soils in central Missouri, a h igh correlation between the observed depth to claypans and the respons e of the EM38 meter was observed. Equations were developed to infer de pths and chart the topography of the claypan. Compared with traditiona l methods of observing this subsurface layer, EM techniques are noninv asive, less labor intensive, more economical and can produce large qua ntities of data in a relatively short period of time.