Extended pesticide soil monitoring in Cuban potato (Solanum tuberosum L.) production: residue co-occurrence, dissipation rates, ecological risks, and implications

Abstract

Pesticides are intensively used but understudied in tropical regions in America. We therefore investigated their occurrence and dissipation in soils of 18 potato (Solanum tuberosum L.) producing farms in Mayabeque, Cuba, between 2018 and 2022. Between two and 17 active ingredients (AIs) were used per site, and the cultivation period and sums of AIs ranged from 0.001 to 26 kg_AI ha⁻¹. Soil concentrations of 38 individual target compounds ranged from 0.1 to 658 μg kg_{dry weight}⁻¹. Observed half-lives (DT_50,obs) of the five most prevalent AIs were up to eight times lower than the DT₅₀ from temperate climate in the Pesticides Properties Database. The fate and behaviour of pesticides rather depended on their physico-chemical than on soil properties. Several sites posed a high risk to earthworms (cumulative risk quotient >1) during periods of peak pesticide application to harvest, with azoxystrobin and cyproconazole contributing the most.