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 10m by 50m 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: 4×22mm) 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 0.57m per tillage pass, with a relatively wide range of mean soil translocation distances ranging from 0.39 to 0.72m 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.
Highlights
Soil erosion, especially on arable land, is a major environmental threat (Pimentel, 2006; Montanarella et al, 2016) negatively affecting on-site soil properties and leading to substantial off-site damage (Pimentel and Burgess, 2013)
The mean translocation distance per tillage pass was 26 ± 12% less for the radio frequency identification (RFID) compared to the micro-tracers (Table 2)
The flagstone point measurements for t0 to t2 are in the same range as the Terrestrial laser scanners (TLS) measurements, but show major deviations compared to the TLS systems for the individual tillage sequences (Table 4). 3.3
Summary
Especially on arable land, is a major environmental threat (Pimentel, 2006; Montanarella et al, 2016) negatively affecting on-site soil properties and leading to substantial off-site damage (Pimentel and Burgess, 2013). Apart from technical issues with these techniques, their major disadvantage is that they do measure tillage erosion because the pattern of tracer redistribution results from the combination of various erosion types (Van Oost et al, 2006). Photogrammetry was used by Vandaele et al (1996) to carry out a longer-term and larger-scale estimate of tillage erosion They determined temporal patterns of elevation differences using sequential stereoscopic aerial photographs from the Belgium loess belt (1947-1996). The main aims of the study are (i) to quantify and compare tillage-induced soil redistribution using different tracers and high-resolution topography measurements, and (ii) to quantify potential differences between tillage erosion measuring techniques and discuss corresponding uncertainties for soil erosion modelling resulting from different model parameters derived from different measuring techniques
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
