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Research article - Peer-reviewed, 2023

Digital Soil Mapping of Cadmium: Identifying Arable Land for Producing Winter Wheat with Low Concentrations of Cadmium

Adler, Karl; Persson, Kristin; Soderstrom, Mats; Eriksson, Jan; Pettersson, Carl-Goran

Abstract

Intake of cadmium (Cd) via vegetable food poses a possible health risk. Cereals are one of the major sources of Cd, and the Cd concentration in the soil has a great effect on the levels in the grain. The aim of the study was to produce decision support for identification of areas suitable for low-Cd winter wheat production in the form of a detailed digital soil map covering an important agricultural region in southern Sweden. A two-step approach was used: (1) we increased the number of soil Cd observations by combining two sets of soil samples, one with laboratory Cd analyses (304 samples) and one with predicted Cd from a portable x-ray fluorescent (PXRF) sensor (2097 samples); and (2) a digital soil mapping (DSM) model (gradient boosting regression) was calibrated on all 2401 soil samples to create a soil Cd concentration map using a number of covariates, of which airborne gamma ray data was identified as the most important. In the first step, cross-validation of the PXRF model obtained a model efficiency (E) of 0.82 and mean absolute error (MAE) of 0.08 mg kg(-1). The DSM model had an E of 0.69 and MAE of 0.11 mg kg(-1). The map of predicted soil Cd concentrations were compared against 307 winter wheat (Triticum aestivum L.) grain samples with laboratory-analyzed Cd concentrations. Areas in the map with low soil Cd concentrations had a high frequency of lower grain Cd concentrations. The map thus seemed to have potential for finding areas suitable for production of low-Cd winter wheat; e.g., for baby food.

Keywords

cadmium; digital soil mapping; machine learning; winter wheat; PXRF

Published in

Agronomy
2023, volume: 13, number: 2, article number: 317
Publisher: MDPI

Authors' information

Swedish University of Agricultural Sciences, Department of Soil and Environment
Swedish University of Agricultural Sciences, Department of Soil and Environment
Swedish University of Agricultural Sciences, Department of Soil and Environment
Swedish University of Agricultural Sciences, Department of Soil and Environment
Pettersson, Carl-Göran
Lantmännen

Sustainable Development Goals

SDG3 Good health and well-being

UKÄ Subject classification

Physical Geography
Soil Science
Agricultural Science

Publication Identifiers

DOI: https://doi.org/10.3390/agronomy13020317

URI (permanent link to this page)

https://res.slu.se/id/publ/121608