ABSTRACT The objective of this study was to evaluate changes in soil metal contents in an Ultisol cultivated with forage cactus (Nopalea cochenillifera) irrigated with diluted treated oil produced wat
*,**Significant at P = 0.05 and P = 0.01 levels, respectively aThe number of SOC observations was 209. BD = bulk density, GC = gravel content, CEC = cation exchange capacity and SOC = soil organic car