The continuous use of agricultural inputs for grain, fiber, and energy production in the Brazilian savannah can increase heavy metal (HM) concentrations in the soils. In this context, we aimed to determine the natural concentrations and establish the quality reference values (QRVs) of HMs in reference soils of a sedimentary watershed under native vegetation in one of the latest agricultural frontiers of Brazil in order to assess the impact of cultivation on the metal concentrations in cropped soils. Additionally, we studied the spatial variability of HMs and the efficiency of the multivariate analyses to distinguish between natural and anthropogenic sources of metals in the soils. Thirty-two and 30 composite soil samples were collected in areas under agricultural exploration and natural vegetation with minimal anthropic interference (low impact areas), respectively. The QRVs established could be ranked as follows (mg kg⁻¹): Fe (18,700) > V (47.83) > Cr (43.44) > Ba (9.11) > Pb (2.73) > Ni (0.80) > Cu (0.74) > Zn (0.46) > Mo (0.34) > Cd (0.05) > Sb (< 0.0007) > Co (< 0.00008). Natural concentrations observed in non-anthropogenic soils are lower than those found in other regions, with the exception of Cr. Also, we found that the mean concentrations of Cd, Cu, Cr, Mo, Mn, Ni, Sb, V, and Zn in agricultural soil were far higher than their background values of the watershed topsoil. Based on our findings, the increased metal concentration in the agricultural soils increases the ecological risk. On the other hand, the mean metal concentrations remain close to the prevention value for soils established by the Brazilian Council for the Environment for agricultural land, which indicates that these areas require monitoring to guarantee foodstuff safety. Our results are useful for public policies not only in the studied area but also worldwide where soils are derived predominantly from sedimentary rocks such as sandstones, siltstones, shales, and limestones.

在巴西大草原上持续使用农业投入物来生产谷物，纤维和能源，会增加土壤中的重金属（HM）浓度。在这种情况下，我们旨在确定自然浓度并在巴西最新农业边界之一的原生植被下的沉积流域参考土壤中建立HMs的质量参考值（QRVs），以便评估耕作对农业的影响。耕作土壤中的金属浓度。此外，我们研究了HMs的空间变异性和多元分析的效率，以区分土壤中的自然金属和人为金属。在人为干扰最小的农业勘探区和自然植被区（低影响区）分别采集了32个和30个复合土壤样品。建立的QRV的排名如下（毫克/千克^-1）：Fe（18,700）> V（47.83）> Cr（43.44）> Ba（9.11）> Pb（2.73）> Ni（0.80）> Cu（0.74）> Zn（0.46）> Mo（0.34）> Cd（0.05 ）> Sb（<0.0007）> Co（<0.00008）。在非人为土壤中观察到的自然浓度低于其他地区（铬除外）。此外，我们发现农业土壤中Cd，Cu，Cr，Mo，Mn，Ni，Sb，V和Zn的平均浓度远高于流域表土的背景值。根据我们的发现，农业土壤中金属浓度的增加会增加生态风险。另一方面，平均金属浓度仍接近巴西环境理事会为农业用地确定的土壤的预防价值，这表明这些区域需要监控以确保食品安全。我们的结果不仅对研究区域的公共政策有用，而且对全世界主要由沉积岩（例如砂岩，粉砂岩，页岩和石灰岩）沉积土壤的世界有用。