There are few works where magnetic tracers are used for the assessment of water erosion, focusing on the traceability of sediments over the soil surface and in small areas (i.e., for laminar erosion survey). The main limitation of magnetic tracers is associated with its preparation and application, as the tracer is typically mixed with a large amount of soil and then spread manually over experimental sites susceptible to erosion. In gully erosion studies, the experimental sites (field areas where a gully is expected to develop) can be quite large. Consequently, the high volume/weight of the material (soil + tracer) to be prepared, transported, and applied renders this technique unfeasible. Moreover, eroded channels can reach a depth of several centimeters, requiring the tracer to be (re)located in the soil profile ideally at this same depth. This work presents a novel technique for the application and distribution of magnetite in the soil profile to track sediments in gully erosion assessments. Experiments were carried out in microplots, where a mixture of magnetite and water was applied over the soil surface using a backpack sprayer. Redistribution of the tracer in the soil profile was carried out with different conventional tillage implements. The control plots were subjected to the same experiments, but using a soil–tracer mixture (conventional technique). The application technique proposed herein enables a correct application of magnetite over large areas, being a promising alternative to the conventional technique. Hoeing tillage implements, such as the rotavator, ensure an approximately homogeneous redistribution of tracer in the soil profile when good soil moisture content is present.

中文翻译：

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临时沟壑侵蚀研究中磁铁矿作为沉积物示踪剂的评估：在土壤中的应用和分布

很少有工作使用电磁示踪剂评估水蚀情况，重点是在土壤表面和小区域内沉积物的可追溯性（即用于层流侵蚀调查）。磁示踪剂的主要局限性在于它的制备和应用，因为示踪剂通常与大量土壤混合，然后手动散布在易受腐蚀的实验点上。在沟壑侵蚀研究中，实验点（预计将发生沟壑的田野区域）可能会很大。因此，要准备，运输和应用的物料（土壤+示踪剂）的体积/重量较高，使该技术不可行。此外，侵蚀的通道可以达到几厘米的深度，要求将示踪剂理想地（重新）放置在土壤剖面中相同的深度。这项工作提出了一种新技术，用于在土壤剖面中应用和分布磁铁矿，以在沟壑侵蚀评估中跟踪沉积物。实验是在微型图中进行的，其中使用背包式喷雾器将磁铁矿和水的混合物施加到土壤表面。示踪剂在土壤剖面中的重新分布是使用不同的传统耕作机具进行的。对照地块进行了相同的实验，但是使用了土壤-示踪剂混合物（传统技术）。本文提出的施加技术使得能够在大面积上正确地磁铁矿施加，这是常规技术的有希望的替代。till耕机具，例如旋耕机，