A pine kraft lignin (PC940C) controlled the release of 14C-chloramben (3-amino-2,5-dichlorobenzoic acid), 14C-metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one], and 14C-alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide] as measured by water leaching in soil columns. As more PC940C was used, a concentration effect was found with more of the three herbicides being retained in the top portion of the soil columns. Combinations of alachlor and metribuzin applied with PC940C did not alter the retention in the top portion of the soil columns of either 14C-metribuzin or 14C-alachlor compared to each herbicide applied with PC940C alone. This would suggest that, at the rate of PC940C used, there was no competition between either herbicide for the controlled-release function of PC940C. The percentage of 14C-chloramben, 14C-metribuzin, and 14C-alachlor retained by PC940C in the top portion of the columns was very similar. Combinations of metribuzin and alachlor without PC940C reduced the mobility of both 14C-metribuzin and 14C-alachlor. Finally, 3H-PC940C was found to be immobile in soil columns leached with water.