Uncertainties in assessing tillage erosion – How appropriate are our measuring techniques?

Fiener, P. and Wilken, F. and Aldana-Jague, E. and Deumlich, D. and Gómez, J.A. and Guzmán, G. and Hardy, Robert and Quinton, J.N. and Sommer, M. and Van Oost, K. and Wexler, R. (2018) Uncertainties in assessing tillage erosion – How appropriate are our measuring techniques? Geomorphology, 304. pp. 214-225. ISSN 0169-555X

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Abstract

Tillage erosion on arable land is a very important process leading to a net downslope movement of soil and soil constitutes. Tillage erosion rates are commonly in the same order of magnitude as water erosion rates and can be even higher, especially under highly mechanized agricultural soil management. Despite its prevalence and magnitude, tillage erosion is still understudied compared to water erosion. The goal of this study was to bring together experts using different techniques to determine tillage erosion and use the different results to discuss and quantify uncertainties associated with tillage erosion measurements. The study was performed in northeastern Germany on a 10 m by 50 m plot with a mean slope of 8%. Tillage erosion was determined after two sequences of seven tillage operations. Two different micro-tracers (magnetic iron oxide mixed with soil and fluorescent sand) and one macro-tracer (passive radio-frequency identification transponders (RFIDs), size: 4 × 22 mm) were used to directly determine soil fluxes. Moreover, tillage induced changes in topography were measured for the entire plot with two different terrestrial laser scanners and an unmanned aerial system for structure from motion topography analysis. Based on these elevation differences, corresponding soil fluxes were calculated. The mean translocation distance of all techniques was 0.57 m per tillage pass, with a relatively wide range of mean soil translocation distances ranging from 0.39 to 0.72 m per pass. A benchmark technique could not be identified as all used techniques have individual error sources, which could not be quantified. However, the translocation distances of the macro-tracers used were consistently smaller than the translocation distances of the micro-tracers (mean difference = − 26 ± 12%), which questions the widely used assumption of non-selective soil transport via tillage operations. This study points out that tillage erosion measurements, carried out under almost optimal conditions, are subject to major uncertainties that are far from negligible.

Item Type:
Journal Article
Journal or Publication Title:
Geomorphology
Additional Information:
This is the author’s version of a work that was accepted for publication in Geomorphology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Geomorphology, 304, 2018 DOI: 10.1016/j.geomorph.2017.12.031
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1900/1904
Subjects:
ID Code:
89460
Deposited By:
Deposited On:
04 Jan 2018 16:54
Refereed?:
Yes
Published?:
Published
Last Modified:
27 Oct 2020 07:43