HERBICIDE DRIFT IMPACT ON NON-TARGET FLORA AND CROP BIODIVERSITY IN ORGANIC FARMLANDS

Abstract

Herbicide drift, the unintended airborne dispersion of agrochemicals into non-target zones, poses a substantial threat to the integrity of organic farming systems. This study aimed to investigate the extent, environmental impact, and biological consequences of herbicide drift on adjacent organic farms by employing a mixed-methods approach that integrated field sampling, laboratory analysis, meteorological data, spatial mapping, and stakeholder interviews. Soil and leaf samples collected at incremental distances from herbicide-treated fields were analyzed using high-performance liquid chromatography (HPLC) and gas chromatography–mass spectrometry (GC-MS), revealing that glyphosate, dicamba, and 2,4-D residues decreased sharply with increasing distance. Bioindicator crops such as lettuce and spinach exhibited significant phytotoxic symptoms—including chlorosis and necrosis—within the first 30 meters from the application zone. Soil health assessments indicated that microbial biomass and enzymatic activities (urease, dehydrogenase, and phosphatase) were notably reduced in drift-affected areas. Furthermore, interviews with 30 organic farmers confirmed reported yield losses ranging from 25% to 40%, primarily in leafy crops, and identified concerns regarding economic losses, environmental integrity, and regulatory inaction. GIS mapping and meteorological monitoring validated the spatial correlation between wind patterns and herbicide dispersion. The results clearly establish that herbicide drift can compromise the productivity, biodiversity, and ecological balance of organic systems. This research underscores the urgent need for stricter application protocols, enhanced buffer zones, adoption of drift-reduction technologies, and increased awareness among stakeholders to safeguard the sustainability of organic agriculture. The findings contribute to policy, practice, and scientific understanding of agrochemical externalities and their mitigation in vulnerable farming ecosystems.