Open AccessField‐Scale Soil Moisture Pattern Mapping using Electromagnetic Induction
Author(s) -
Martínez Gonzalo,
Vanderlinden Karl,
Giráldez Juan Vicente,
Espejo Antonio J.,
Muriel José Luis
Publication year - 2010
Publication title -
vadose zone journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.036
H-Index - 81
ISSN - 1539-1663
DOI - 10.2136/vzj2009.0160
Subject(s) - topsoil , subsoil , soil science , water content , environmental science , vertisol , spatial variability , pedotransfer function , soil water , infiltration (hvac) , tillage , hydrology (agriculture) , geology , hydraulic conductivity , agronomy , geography , mathematics , statistics , geotechnical engineering , biology , meteorology
Soil apparent electrical conductivity (EC a ) responds to time‐variable soil properties, such as soil water content (θ), and can therefore be used to characterize the spatial and temporal dynamics of θ at the field scale. When clay content is high and uniform and the θ range small, however, it is not clear whether EC a maps can be used for this purpose. A soil management experiment established in a Vertisol in 1982 was surveyed for EC a on 13 occasions to capture changing soil conditions and to determine the sources of this variability. Less variation with time was found in subsoil than in topsoil EC a patterns, especially within the conventional tillage (CT) plots, in areas with shallow soil, and along the drainage network. Using the 13 EC a relative difference data sets as variables, principal component (PC) analysis showed that the first three PCs explained 90% of their total variance. The time‐stable or mean EC a pattern was significantly correlated with PC1 and could also be associated with topography, soil depth, and soil structure but could not be related to a single survey. Topography and soil management could be associated with PC2 and PC3, respectively. Time‐stable θ patterns, inferred from 26 surveys, revealed topographical and management characteristics and showed significant relationships ( P < 0.001) with EC a –derived patterns like soil porosity and infiltration caused by soil management, topography, and rainfall. Electromagnetic induction sensors were useful for mapping soil spatial variability and changing soil conditions due to management effects and external forcing in uniform clay soils.