Evaluating the Ecotoxicological Effects of Glyphosate on Soil Systems: Towards Sustainable Agroecosystems

Glyphosate (C₃H₈NO₅P) is a broad-spectrum herbicide commonly used in agriculture to effectively control weeds in cereal, vineyard, and horticultural crops. However, excessive glyphosate application can negatively impact soil health by altering microbial diversity, disrupting nutrient cycling, and reducing fertility and biodiversity. Furthermore, prolonged exposure to glyphosate has been linked to potential health risks for humans, including cancer and endocrine disruption. The International Agency for Research on Cancer (IARC, 2015) classified glyphosate as "probably carcinogenic to humans" (Group 2A), underscoring the need for stricter regulations and environmentally responsible agricultural practices. This study aimed to evaluate the phytotoxicity of glyphosate on the germination of Raphanus sativus and Lepidium sativum seeds. This study contributes to our understanding of the environmental risks associated with increasing concentrations of this compound in agroecosystems. A triplicate bioassay was conducted using glyphosate concentrations of 3.6, 1.8, 0.9, 0.45, and 0.225 g/L. Twenty seeds of each species were evenly distributed in Petri dishes containing cotton soaked with the respective test solutions. After seven days, germinated seeds were counted, and median lethal concentrations (LC₅₀) were calculated. Statistical analyses were performed to evaluate the correlation between glyphosate concentration and germination inhibition. The results demonstrated a significant increase in germination inhibition between 1.8 and 3.6 g/L for both seed species. Turnip seeds were more sensitive than watercress seeds. A positive and significant correlation was found between glyphosate concentration and inhibition rate. The LC₅₀ values obtained were 2.18 g/L for Raphanus sativus and 1.43 g/L for Lepidium sativum. These results confirm that glyphosate impairs seed germination. The study emphasizes the need for continuous environmental monitoring and the adoption of sustainable soil management practices to mitigate glyphosate's ecological impact.