No-till (NT) is a soil management system designed to protect soil resources from water erosion and provide numerous benefits compared to conventional tillage through the increase of organic matter inputs into the soil. However, NT in isolation is not sufficient to control erosion processes caused by an excessive production of surface runoff. This study evaluated soil losses on agricultural hillslopes under no-till characterized by contrasted water, soil, and crop management conditions. To this end, water and soil losses were monitored between 2014 and 2018 at two scales, including four macroplots (0.6 ha; 27 events) and two paired zero-order catchments (2.4 ha; 63 events). The resulting dataset covered a wide range of rainfall conditions that occurred in contrasted soil, crop, and runoff management conditions. Hyetographs, hydrographs, and sedigraphs were constructed, and these data were used to evaluate the impact of management on sediment yields, including that of terraces, scarification, and phytomass on sediment yield. The installation of terraces reduced sediment yield by 58.7%, mainly through surface runoff control. Crop management including an increased phytomass input efficiently controlled soil losses (63%), although it did not reduce runoff volume and peak flow. In contrast, scarification had no impact on runoff and soil losses. The current research demonstrated the need to combine the installation of terraces and leaving a high amount of phytomass on the soil to control surface runoff and erosion and reduce sediment yield. The current research therefore reinforces the relevance of the monitoring strategy conducted at the scale of macroplots and zero-order catchments to evaluate the impact of contrasted water, soil, and crop management methods and select the most effective conservation agriculture practices.

中文翻译：

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量化免耕对巴西南部山坡和集水区沉积物产量的影响

免耕 (NT) 是一种土壤管理系统，旨在保护土壤资源免受水侵蚀，并通过增加土壤中的有机物质输入与传统耕作相比提供许多好处。然而，单独的 NT 不足以控制由过度产生地表径流引起的侵蚀过程。本研究评估了以对比水、土壤和作物管理条件为特征的免耕农业山坡的土壤流失。为此，2014 年至 2018 年期间在两个尺度上监测了水土流失，包括四个宏观地块（0.6 公顷；27 个事件）和两个成对的零级流域（2.4 公顷；63 个事件）。由此产生的数据集涵盖了在对比土壤、作物和径流管理条件下发生的各种降雨条件。水文图、水文图、并构建了沉积物，这些数据用于评估管理对沉积物产量的影响，包括梯田、松土和植物群对沉积物产量的影响。梯田的安装减少了 58.7% 的产沙量，主要是通过地表径流控制。包括增加植物量输入在内的作物管理有效地控制了土壤流失 (63%)，尽管它没有减少径流体积和峰值流量。相比之下，松土对径流和土壤流失没有影响。目前的研究表明，需要将梯田的安装与在土壤上留下大量植物群相结合，以控制地表径流和侵蚀并减少沉积物产量。