Field‐scale apparent soil electrical conductivity

Abstract

Soils are notoriously spatially heterogeneous and many soil properties are temporally variable. Spatial variability of soil properties has a profound influence on agricultural and environmental processes, such as plant–water–soil interactions, water flow, and solute transport, resulting in within‐field plant yield variation and degradation of soil quality, to mention only a few. Field‐scale mapping of spatial variability and monitoring of temporally dynamic soil properties is necessary for a variety of edaphic activities, such as soil surveys, reclamation, crop selection, sitespecific management, and soil quality assessment. There are various approaches for characterizing soil spatial variability, but none of these has been as extensively investigated and is as reliable and cost effective as apparent soil electrical conductivity (ECa) directed soil sampling. Geospatial measurements of ECa are well suited for characterizing the spatial distribution of soil properties because they are reliable, quick, and easy to take with GPS‐based mobilized ECa measurement equipment. Directed soil sampling based on geo‐referenced measurements of ECa is a proven and robust means of characterizing the spatial variability of any soil property that influences ECa, including sol salinity, water content, texture, bulk density, organic matter, and cation exchange capacity. It is the goal of this methodology paper to provide an overview of the characterization of soil spatial variability across multiple scales using ECa–directed soil sampling with a focus on the field scale. Mobile ECa equipment, protocols, guidelines, special considerations, data reliability tests, and strengths and limitations are presented for characterizing spatial and temporal variation in soil properties using ECa–directed soil sampling.

Remote Sensing (NDVI) and Apparent Soil Electrical Conductivity (ECap) to Delineate Different Zones in a Vineyard

“…Regarding the soil's percentages of sand, silt, and clay, as shown in Table 3, the results revealed that Z2 and Z3 presented higher contents of clay and lower of sand, significantly contrasting with Z1. This outcome is in accordance with the above results, since soils with high clay contents are expected to have higher CEC [22], as the exchange surfaces in clay minerals adsorb exchangeable cations and consequently increase exchangeable cations that can be exchanged and absorbed by the plants. This relationship has already been studied using remote data, showing the strong correlation between EC ap and clay content and CEC, concerning all types of EC ap data and across a multitude of fields [23].…”

Can soil health explain grain quality? A case study of a corn field in Texas

“…Variables such as topography, and apparent electrical conductivity (ECa), which can be collected in the field using soil sensors, can be useful to predict grain quality. Apparent electrical conductivity is a measure of conductivity of soils and is influenced by texture, water content, organic matter, cation exchange capacity, and salinity, which are known to influence crop yield (Corwin & Scudiero, 2020;Kitchen et al, 2003). Topography plays a critical role in variations in soil moisture and nutrient content, which affect crop yield and quality (Hawley et al, 1983;Kravchenko & Bullock, 2000).…”

Monitoring Onion Crop “Cipolla Rossa di Tropea Calabria IGP” Growth and Yield Response to Varying Nitrogen Fertilizer Application Rates Using UAV Imagery

“…This parameter's value can depend on several factors related to the soil's intrinsic properties and management. In agricultural soils, factors such as the climatic trend, irrigation water quality and fertilization could significantly affect soluble salts concentration in the soil [54,55]. Among vegetable crops, the onion is a species that is highly susceptible to salinity [21,56].…”