TY - JOUR

T1 - Time-lapse geophysical assessment of agricultural practices on soil moisture dynamics

AU - Blanchy, Guillaume

AU - Watts, C.W.

AU - Richards, J.

AU - Bussell, J.

AU - Huntenburg, Katharina

AU - Sparkes, D.

AU - Stalham, M.

AU - Hawkesford, M.

AU - Whalley, W.R.

AU - Binley, Andrew

PY - 2020/10/28

Y1 - 2020/10/28

N2 - 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, tillage with nitrogen 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 was imaged by time-lapse ERT. In the third case study, larger change in electrical conductivity over time were observed in conventional tillage compared to direct drill using time-lapse EMI. In addition, different nitrogen application rates had 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.

AB - 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, tillage with nitrogen 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 was imaged by time-lapse ERT. In the third case study, larger change in electrical conductivity over time were observed in conventional tillage compared to direct drill using time-lapse EMI. In addition, different nitrogen application rates had 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.

U2 - 10.1002/vzj2.20080

DO - 10.1002/vzj2.20080

M3 - Journal article

JO - Vadose Zone Journal

JF - Vadose Zone Journal

SN - 1539-1663

M1 - e20080

ER -