Spatial and temporal variability of soil electrical conductivity related to soil moisture

Abstract

Soil electrical conductivity (ECa) is a soil quality indicator associated to attributes interesting to site-specific soil management such as soil moisture and texture. Soil ECa provides information that helps guide soil management decisions, so we performed spatial evaluation of soil moisture in two experimental fields in two consecutive years and modeled its influence on soil ECa. Soil ECa, moisture and clay content were evaluated by statistical, geostatistical and regression analyses. Semivariogram models, adjusted for soil moisture, had strong spatial dependence, but the relationship between soil moisture and soil ECa was obtained only in one of the experimental fields, where soil moisture and clay content range was higher. In this same field, coefficients of determinations between soil moisture and clay content were above 0.70. In the second field, the low soil moisture and clay content range explain the absence of a relationship between soil ECa and soil moisture. Data repetition over the years, suggested that ECa is a qualitative indicator in areas with high spatial variability in soil texture.

Delineation of irrigation management zones in a Quartzipsamment of the Brazilian semiarid region

“…bras., Brasília, v.51, n.9, p.1283-1294, set. 2016 DOI: 10.1590/S0100-204X2016000900028 Our study corroborate the results of the following authors: Terra (2012), who found that the same models adjusted for the attributes sand (exponential), clay, and Ds (spherical); Parfitt et al (2009), who obtained a Gaussian fit for silt; and Molin & Faulin (2013), who found a spherical model for ECa in different time periods.…”

“…Corwin et al (2006) found similar CV values for clay, Ds, AW, and ECa at different depths in clay loam soils. Molin & Faulin (2013) classified CV in a similar way for clay and ECa data in two areas with medium soil texture.…”

Site-Specific Erodibility in Claypan Soils: Dependence on Subsoil Characteristics

“…5C). The direct contact method is used for measuring surface geoelectrical properties at the field scale and has been used by numerous researchers (Gebbers et al, 2009;Molin and Faulin, 2013;Doolittle and Brevik, 2014). Higher EC a has been correlated to higher clay content in clay-pan soils .…”

“…Continuous methods to characterize soils within agricultural fields have been performed by measuring the apparent electrical conductivity, EC a (Corwin and Lesch, 2005). Spatial variations in EC a are typically attributed to cation exchange capacity, salt, clay and water content in the soil (Kachanoski et al, 1988;Lund and Christy, 1998;Lund et al, 1999;Kitchen et al, 2003;Lerch et al, 2005;Molin and Faulin, 2013) and therefore are valuable tools for mapping variability in soils. Several researchers have compared EC a measurements obtained from different near surface geophysical methods or different equipment using these methods (Buchleiter and Farahani, 2002;Doolittle et al, 2001Doolittle et al, , 2002Sudduth et al, 2003;Allred et al, 2006).…”

Data Mining for the Assessment of Management Areas in Precision Agriculture

“…JOHANNSEN et al (2000) show an approach using remote sensing to obtain vegetation indexes and associate them to soil sampling grids. Other approaches consider the farmer sensitivity from empirical knowledge, although the most disseminated method in the literature for the setting-up of MAs consists in grouping chemical and physical soil parameters as well as relief data, taken from strategic georeferenced areas FAULIN, 2013). Several farmers own a large volume of data related to their property, from which new information and standards can be retrieved to support the decision-making process MILANI, 2013;LUNARDELLI et al, 2014).…”