Absorption and accumulation of glyphosate and AMPA residues from soil to crops

The persistence of glyphosate residues in agricultural soils raises concerns about their potential transfer to crops. This study evaluated the absorption and accumulation of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) from soil into crops under greenhouse conditions. Wheat, carrot, and lettuce were grown in an Argiudoll soil treated with three glyphosate doses (5, 18, and 100 L ha^-1) and three phosphorus levels (0, 200, and 600 kg ha^-1). Residues in soil and plant tissues were quantified by UHPLC-MS/MS.Glyphosate was absorbed through roots and accumulated in plant organs as soil availability increased. Lettuce leaves showed the highest concentrations, followed by carrot roots and wheat grain. Phosphorus fertilization enhanced glyphosate uptake by increasing its availability in soil solution. When compared with European Union maximum residue limits (MRLs), residue contributions were low in cereals but approached or exceeded regulatory thresholds in lettuce under high soil inputs, unnder potential field conditions. These results demonstrate that soil residues can act as a pathway for glyphosate entry into crops, highlighting the importance of residue monitoring and improved agronomic management to ensure food safety and sustainable agricultural systems.