Characterization of tillage effects on the spatial variation of soil properties using ground-penetrating radar and electromagnetic induction

Abstract

Tillage practices influence physical, chemical, and biological soil properties, which also affect soil quality and consequently plant growth. In this study, the main objective was to evaluate the effects of different tillage practices on soil physical properties such as soil water content (SWC) by using geophysical methods, namely, ground-penetrating radar (GPR) and electromagnetic induction (EMI). Additional measurements such as soil sampling, capacitance probe, and soil penetrometer data were acquired as ground truths. The study was performed for three contrasting tillage practices, i.e., conventional tillage (CT), deep loosening tillage (DL), and reduced tillage (RT), applied on different plots of an agricultural field. The data showed that tillage influences soil resistance in shallow soil layers (deeper tillage decreases soil resistance), which could be partly seen in on-ground GPR data. In addition, reference SWC measurements (capacitance probes and soil sampling) were in fairly good agreement with the water content estimates from off-ground GPR. We also observed a tillage effect on shallow surface SWC, while deeper SWC seems to be unaffected by tillage. Mean surface SWC was significantly lower for CT compared to DL and RT, which was partly explained by lower pore connectivity between the topsoil and the deeper layers after conventional tillage. Moreover, the variance of the SWC within the conventional tillage plots was larger than within the other plots. This larger SWC variability could be explained by a greater soil heterogeneity induced by the plowing process. Overall, this study confirms the potential of GPR and EMI for the determination of soil physical properties at the field scale and for the assessment of agricultural management practices.

Responses of corn physiology and yield to six agricultural practices over three years in middle Tennessee

“…reported that the average corn yield (7.26 ton/ha) from 1993 to 1999 in non-tillage is higher than in spring plow tillage (6.42 ton/ha)40. The major reason could be that the CT treatment decreased soil bulk density and soil moisture content, and as a result, decreased corn root growth and yield4142. There are also a few studies reporting that no-tillage does not change or even decreases crop yield4043.…”

Spatial variation of penetration resistance and water content as affected by tillage and crop rotation in a black soil in Northeast China

“…Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions Introduction Scientific information on the spatial variability of soil properties is critical for understanding ecosystem processes, designing sustainable soil-crop systems, and making environmental management decisions (Tesfahunegn et al 2011). Soil penetration resistance (SPR), soil water content (SWC), and other soil properties are affected by the spatial variability of the soil (Jonard et al 2013). SPR can be helpful for choosing an appropriate depth of tillage and intensity of soil crushing, estimating the tillage quality, and developing management options that minimize crop production (Usowicz & Lipiec 2009).…”

“…Better description of spatial changes in SPR and SWC due to machinery traffic will allow us to determine the permissible size of agricultural machinery and number of passes to avoid soil degradation and preserve favorable conditions for plant growth (Botta et al 2012). Many previous studies have focused on the spatial variability of SPR and SWC, which largely relies on the use of geostatistics (Özgöz 2009;Aksakal et al 2011;Jonard et al 2013); however, the profile, particularly the horizontal and vertical, distributions of SPR and SWC have not received much attention up to now. The effect of tillage on the spatial variability of SPR and SWC has been evaluated by many researchers, whereas most of these studies are restricted to the variability in the crop row position (Usowicz & Lipiec 2009;Aksakal et al 2011;Millán et al 2012).…”

Ground penetrating radar for underground sensing in agriculture: a review

“…Generally, GPR can be used to monitor subsurface features that have contrasting dielectric constants (Truman et al, 1988). In particular, GPR has been used for soil water content estimation including measuring soil water content profile (Lambot et al, 2004), estimating soil water variation under irrigation conditions (Galagedara et al, 2005), identifying specific soil water depth and monitoring spatial and temporal variation of soil water content (Pan et al, 2012), mapping the spatial variation of soil water content at the field scale (Weihermüller et al., 2007), and comparing the tillage effects on soil water content (Jonard et al, 2013). Compared to time domain reflectometry, GPR is better suited for mapping large-scale features (>5 m) in soil water content (Huisman et al, 2002).…”