Abstract
The effect of four sources of organic manures (alfalfa residue, cow, chicken and sheep) and their concentrations (0, 1 and 2%) on the enzymatic activity of three calcareous soils from Northern Iraq have been studied in a 45-day incubation experiment at 28C and 90% of the field capacity. During this period, the activity of urease, asparginase and glutaminase have been measured at a 2-week intervals. Results indicated that the more the concentration of the added manure, the more the activity of the enzymes. Addition of alfalfa residue resulted in more activity, followed by chicken manure, then sheep. The least effect was obtained in soils treated with cow manure.
