Toxic chromium [(Cr(VI)] in food chain has created an alarming situation for human life and ecosystems. The present study through a greenhouse pot experiment aims to (a) investigate the ability of organic matter in reducing Cr uptake by lettuce (Lactuca sativa L.) from a sandy loam soil irrigating with Cr(VI)-water, (b) to provide a way for the restriction of Cr transfer from contaminated soils and irrigation water to plants/crops and (c) to contribute to the better management of soil (land) and water use, without reduction of the agricultural production.

Since soil and groundwater contamination by Cr is a potential risk in a worldwide scale, due to industrial activities and/or natural processes, organic carbon may play a key role in the mobility of added Cr(VI) to soil via irrigation water, in a significant way. The cultivation of lettuce, using organic matter in the form of leonardite (10 and 30 wt%) and Cr(VI)-irrigation water (100, 200 and 300 mgL⁻¹), showed that the uptake of Cr in both shoots and roots increased with increasing concentration of Cr in the irrigation water. The highest Cr values in shoots (average = 10 mg/kg) and in roots (average = 28 mg/kg) were recorded in those plants cultivated in soil after the addition of Cr(VI)- water without organic matter, whereas the lowest Cr values in shoots (average = 0.44 mg/kg) and in roots (average = 0.7 mg/kg) were recorded in those plants cultivated in soil with addition of 30 wt% organic matter.

The used leonardite as organic matter that is an oxidized form of lignite, due to its high content of humic acid is considered to be a useful organic fertilizer that provides possibilities for combining food production with soil protection. Therefore, the application of the natural organic material leonardite, as a land management technique, seems to be a cost-effective method consistent to related protocols for the protection of the soil quality.

食物链中的有毒铬[(Cr(VI)]已对人类生命和生态系统造成了惊人的影响。本研究通过温室盆栽实验，旨在 (a) 研究有机物减少生菜 ( Lactuca ) 对 Cr 吸收的能力sativa L.）从用 Cr(VI)-水灌溉的沙壤土中提取，(b) 提供一种限制 Cr 从受污染土壤和灌溉水中转移到植物/作物的方法，以及 (c) 有助于改善环境管理土壤（土地）和水的使用，而不减少农业产量。

由于铬对土壤和地下水的污染是全球范围内的潜在风险，由于工业活动和/或自然过程，有机碳可能在添加的铬（VI）通过灌溉水迁移到土壤中发挥关键作用，在重要的方式。使用风化褐煤（10 和 30 wt%）形式的有机物和 Cr(VI) 灌溉水（100、200 和 300 mgL ^-1 ）的生菜栽培表明，芽和根对 Cr 的吸收随着灌溉水中 Cr 浓度的增加而增加。在添加不含有机物的 Cr(VI)-水后，在土壤中培养的植物记录到地上部 Cr 值最高（平均 = 10 mg/kg）和根部 Cr 值（平均 = 28 mg/kg），而最低 Cr 值则为最低 Cr 值。在添加了 30 wt% 有机质的土壤中栽培的植物记录了芽中的 Cr 值（平均值 = 0.44 mg/kg）和根中的 Cr 值（平均值 = 0.7 mg/kg）。

所使用的风化褐煤作为有机质，是褐煤的氧化形式，由于其腐殖酸含量高，被认为是一种有用的有机肥料，为将粮食生产与土壤保护相结合提供了可能性。因此，应用天然有机材料风化褐煤作为一种土地管理技术，似乎是一种符合相关土壤质量保护协议的具有成本效益的方法。