Time‐lapse geophysical assessment of agricultural practices on soil moisture dynamics. Issue 1 (28th October 2020)

• Record Type: Journal Article
• Authors: Blanchy, Guillaume; Watts, Chris. W.; Richards, Jake; Bussell, Jennifer; Huntenburg, Katharina; Sparkes, Debbie L.; Stalham, Mark; Hawkesford, Malcolm J.; Whalley, W. Richard; Binley, Andrew
• Is Part Of: Vadose zone journal. Volume 19:Issue 1(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-10-28
• Subjects: Soil science -- Periodicals; Zone of aeration -- Periodicals; Groundwater flow -- Periodicals; Groundwater flow; Zone of aeration; Periodicals; Electronic journals; 631.4
• DOI: 10.1002/vzj2.20080
• Languages: English
• ISSNs: 1539-1663

Abstract

Abstract: Geophysical surveys are now commonly used in agriculture for mapping applications. High‐throughput collection of geophysical properties such as electrical conductivity (inverse of resistivity) can be used as a proxy for soil properties of interest (e.g., moisture, texture, salinity). Most applications only rely on a single geophysical survey at a given time. However, time‐lapse geophysical surveys have greater capabilities to characterize the dynamics of the system, which is the focus of this work. Assessing the impact of agricultural practices through the growth season can reveal important information for the crop production. In this work, we demonstrate the use of time‐lapse electrical resistivity tomography (ERT) and electromagnetic induction (EMI) surveys through a series of three case studies illustrating common agricultural practices (cover crops, compaction with irrigation, and tillage with N fertilization). In the first case study, time‐lapse EMI reveals the initial effect of cover crops on soil drying and the absence of effect on the subsequent main crop. In the second case study, compaction leading to a shallower drying depth for potatoes ( Solanum tuberosum L.) was imaged by time‐lapse ERT. In the third case study, larger changes in electrical conductivity over time were observed in conventional tillage compared with direct drill using time‐lapse EMI. In addition, different N application rates had a significant effect on the yield and leaf area index but only ephemeral effects on the dynamics of electrical conductivity, mainly after the first application. Overall, time‐lapse geophysical surveys show great potential for monitoring the impact of different agricultural practices that can influence crop yield. Core Ideas: Time‐lapse geophysical surveys can help assess the impact of agricultural practices. Cover crops affect soil drying while in place but have no substantial effect on the main crop. Traffic‐induced soil compaction limits water extraction depths of potato crops. The soil electrical conductivity in moldboard plowing decreases faster than in direct drill. N levels have significant impact on the soil EC after application, but not over a longer term.