Fig. 3. Arylsulfatase activity of chloroform fumigated soil, non-fumigated, and fumigated minus non-fumigated soil of the integrated crop-livestock system and continuous cotton system in November 2002 and July 2003. The bold crop signifies which crop the field is under at the time of the measurements. Similar letter at the same depth indicates no significant treatment differences according to least significant differences (LSD) at P < 0.05.