Persistence, phytotoxicity, and management of arsenic, lead and mercury residues in old orchard soils of New York State

Abstract

Lead arsenate was used for pest control in fruit orchards for many years in the United States, and its residues remain in most of these soils. Since arsenic and lead are toxic and only slightly mobile in soils, an analytical survey was conducted in 1993 to determine the concentrations of these elements persisting in soil samples from 13 older and newer orchards in New York State. Concentrations of arsenic and lead ranged, respectively, from 1.60 to 141 and from 1.48 to 720 (ppm, dry wt). Significant ( P < 0.01, n = 13) pairwise correlations were observed among concentrations of these elements: As vs. Pb r = 0.97), As vs. Hg (r = 0.79), and Pb vs. Hg (r = 0.83). Despite previous reports of phytotoxicity to fruit trees, elevated arsenic concentrations did not significantly reduce the dry weights of apple ( Malus domestica) seedlings grown in pasteurized soil from these orchards. The general environmental effects and best management strategies for arsenic and lead in orchard soils are discussed including phytotoxicity of arsenic and its uptake and accumulation in plants, ingestion by small mammal herbivores and their predators in orchards, and ways to minimize potential adverse effects on humans.