2,4′,5-Trichlorobiphenyl-14C (1.28 kg/ha) and 2,2′,4,4′,6-pentachlorobiphenyl-14C (1.12 kg/ha) were applied each to soil in a lysimeter-type box under outdoor conditions, and carrots were grown. In the following year, sugar beets were grown without retreatment. For the trichlorobiphenyl, only 32.5% of the applied radioactivity was recovered in soil and plants after the first season; 67.5% was lost due to volatilization, uptake by carrot plants was 3.1% of the applied radioactivity. The radioactivity remaining in the soil was partly dispersed to a depth of 40 cm and consisted of 78.7% trichlorobiphenyl, 1.6% soluble conversion products, and 19.7% unextractable residues; in the second year, total recovery as well as the portion of unchanged parent compound decreased. Uptake by sugar beets was only 0.2%. The soluble conversion products in plants and soil were identified as oxygenated metabolites. For the pentachlorobiphenyl, total recovery was 58.5%, and loss due to volatilization 41.5%, uptake by crops 1.4% (after first season), and conversion below 1%; no metabolites were identified.