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Inverse Roots: Link crop root traits to above and belowground sensor data

Main subject area: Mini-rhizotron-enabled root traits (depth, density, distribution etc.), UAV (Unmanned Aerial Vehicles) image analysis, Soil moisture time series analysis, Process-based crop models, Inverse modeling

Short project description

Climate change calls for resilient cropping systems. Root systems play a key role, as they enable crops to access more resources and reduce nitrate leaching, supporting both productivity and groundwater quality. Selecting varieties with advantageous root traits can therefore contribute to greener and more efficient agriculture. Root phenotyping aims to characterize root traits such as depth, density, and distribution. However, because belowground information is inherently difficult to access, current methods require substantial effort at specific sites and often have difficulties to capture the spatial representativeness of root traits.

Inverse modeling offers a promising alternative to access root information. By coupling a process-based crop model with observations of its outputs, it allows inferring model’s inputs such as root characteristics. In many crop models, root traits determine both soil resource availability and the mobilizable carbohydrate reserves that support key physiological processes, including grain filling. In parallel, both above and belowground sensing technologies provide unprecedented details on plant traits and soil conditions, with high spatial resolution and coverage. This master project will explore whether combining inverse modeling with sensor data can retrieve root traits from canopy imagery and soil moisture time series. The student will develop an inversion method using a well-documented crop model, UAV images and soil moisture sensor data, applied to a field trial under Danish pedo-climatic conditions.

 

Department and supervisor

Project start

Anytime

Physical location of project and students work

Blichers Alle 20, Tjele, 8830-DK

Extent and type of project

30 ECTS: Theoretical thesis based on literature studies and/or analysis of issued and edited data sets.

45 or 60 ECTS: Experimental theses in which the student is responsible for collection and analysis of his/her own original data.

 

Additional information

The research will be conducted on the ongoing “PerennialSystemTrial” at Foulumgård at AU Viborg. The student will primarily work on a classical annual crop, chosen between winter wheat or winter canola. Depending on situations, they will have the possibility to extend the developed approach on a perennial cereal crop: Intermediate Wheatgrass (IWG; Thynopyrum intermedium) known for their deeper rooting systems. Supervision will be conducted by Eusun Han (Associate Professor) with the co-supervision of Yulin Zhang (Postdoctoral Fellow). The student will also work together with different researchers and technical staff.

Relevant articles

Hupet, F., et al. “Estimation of Root Water Uptake Parameters by Inverse Modeling with Soil Water Content Data.” Water Resources Research, vol. 39, no. 11, Nov. 2003, doi.org/10.1029/2003wr002046. Accessed 22 Feb. 2020.

Zhang, Yulin, et al. “Why Make Inverse Modeling and Which Methods to Use in Agriculture? A Review.” Computers and Electronics in Agriculture, vol. 217, 12 Jan. 2024, p. 108624, www.sciencedirect.com/science/article/pii/S0168169924000152, doi.org/10.1016/j.compag.2024.108624.