Cover crops (CC) effectively reduce soil erosion, a significant threat to farmers and the environment. Yet, there is lack of data quantifying their effect on rill erosion in the field scale. The major objective of this study was to use UAV-RGB images to estimate the effects of CC on rill erosion in the field scale and to characterize rill parameters in areas with and without CC. Images were collected from a 20-ha field in the "Model Farm for Sustainable Agriculture", consisting of plots with and without CC. Images were captured 33 days after CC sowing and following substantial rainfall events that formed three prominent rills. Following the elimination of vegetation pixels, structure from motion algorithm was used to generate a post-erosion digital surface model (DSM) and a baseline DSM simulating the pre-erosion soil surface (DSM reconstructed baseline). Change-detection analysis revealed that CC significantly reduced rill erosion. Average soil loss per m2 was 48 %, 58 %, and 29 % lower in CC compared to bare soil plots in the three studied rills. Additionally, rill maximum depth was 74 %, 74 %, and 24 %, and cross-sectional surface area was 67 %, 87 %, and 43 % lower in CC, compared to bare soil plots. The findings highlight CC's effectiveness in mitigating field-scale rill erosion even in their early growth stages. However, creating a DSM reconstructed baseline in CC plots is currently confined to partial CC vegetation coverage (leaving enough soil pixels visible), necessitating additional studies to determine the maximal coverage that won't compromise accuracy. Further assessments of the methods' quantitative accuracy require studies incorporating extensive ground truth data.

中文翻译：

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使用无人机图像分析评估耕地覆盖作物的田间规模沟壑侵蚀缓解效果


覆盖作物 （CC） 可有效减少土壤侵蚀，这是对农民和环境的重大威胁。然而，在田间尺度上，缺乏量化它们对沟壑侵蚀影响的数据。本研究的主要目的是使用 UAV-RGB 图像来估计 CC 对田间尺度上裂痕侵蚀的影响，并表征有和没有 CC 的区域的沟壑参数。图像是从“可持续农业模型农场”的 20 公顷田地收集的，由有和没有 CC 的地块组成。图像是在 CC 播种后 33 天和形成三个突出溪流的大量降雨事件之后捕获的。在消除植被像素后，使用运动结构算法生成侵蚀后数字表面模型 （DSM） 和模拟侵蚀前土壤表面的基线 DSM （DSM 重建基线）。变化检测分析显示，CC 显著减少了沟壑侵蚀。与三个研究沟壑中的裸土地块相比，CC 中每平方米的平均土壤流失量分别降低了 48 %、58 % 和 29 %。此外，与裸土样块相比，CC 的裂缝最大深度分别为 74 %、74 % 和 24 %，横截面表面积分别降低了 67 %、87 % 和 43 %。这些发现强调了 CC 在减轻田间规模沟土侵蚀方面的有效性，即使在其早期生长阶段也是如此。然而，在 CC 图中创建 DSM 重建基线目前仅限于部分 CC 植被覆盖（留下足够的土壤像素可见），因此需要额外的研究来确定不会影响准确性的最大覆盖度。对方法定量准确性的进一步评估需要结合大量地面实况数据的研究。