Functional Evaluation of Digital Soil Hydraulic Property Maps through Comparison of Simulated and Remotely Sensed Maize Canopy Cover

Mulenga Kalumba, Stefaan Dondeyne, Eline Vanuytrecht, Edwin Nyirenda and Jos Van Orshoven
Additional contact information
Mulenga Kalumba: Department of Earth and Environmental Sciences, University of Leuven, Celestijnenlaan 200E, 3001 Leuven, Belgium
Stefaan Dondeyne: Department of Geography, Ghent University, Krijgslaan 281 S8, 9000 Gent, Belgium
Eline Vanuytrecht: Department of Earth and Environmental Sciences, University of Leuven, Celestijnenlaan 200E, 3001 Leuven, Belgium
Edwin Nyirenda: Department of Civil and Environmental Engineering, School of Engineering, The University of Zambia, Lusaka P.O. Box 32379, Zambia
Jos Van Orshoven: Department of Earth and Environmental Sciences, University of Leuven, Celestijnenlaan 200E, 3001 Leuven, Belgium

Land, 2022, vol. 11, issue 5, 1-15

Abstract: Soil maps can usefully serve in data scarce regions, for example for yield (gap) assessments using a crop simulation model. The soil property estimates’ contribution to inaccuracy and uncertainty can be functionally evaluated by comparing model results using the estimates as input against independent observations. We conducted a functional evaluation of digital maps of soil hydraulic properties of the Zambezi River Basin using a crop growth model AquaCrop. AquaCrop was run, alimented with local meteorological data, and with soil hydraulic properties derived from the digital maps of digital soil mapping (DSM) techniques, as opposed to estimations from the widely used Saxton and Rawls pedotransfer functions. The two simulated time series of canopy cover (CC) (AquaCrop-CC-DSM and AquaCrop-CC-Saxton), which were compared against canopy cover data derived from the remotely sensed Leaf Area Index (LAI) from the MODIS archive (MODIS-CC). A pairwise comparison of the time series resulted in a root mean squared error (RMSE) of 0.07 and a co-efficient of determination (R 2 ) of 0.93 for AquaCrop-CC-DSM versus MODIS-CC, and an RMSE of 0.08 and R 2 of 0.88 for AquaCrop-CC-Saxton versus MODIS-CC. In dry years, the AquaCrop-CC-DSM deviated less from the MODIS-CC than the AquaCrop-CC-Saxton ( p < 0.001), although this difference was not significant in wet years. The functional evaluation showed that soil hydraulic property estimates based on digital soil mapping outperformed those based on Saxton and Rawls when used for simulating crop growth in dry years in the Zambezi River Basin. This study also shows the value of conducting a functional evaluation of estimated (static) soil hydraulic properties in terms of dynamic model output.

Keywords: AquaCrop; crop canopy cover; digital soil mapping; leaf area index; remote sensing (search for similar items in EconPapers)
JEL-codes: Q15 Q2 Q24 Q28 Q5 R14 R52 (search for similar items in EconPapers)
Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2073-445X/11/5/618/pdf (application/pdf)
https://www.mdpi.com/2073-445X/11/5/618/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jlands:v:11:y:2022:i:5:p:618-:d:799408

Access Statistics for this article

Land is currently edited by Ms. Carol Ma

More articles in Land from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().