تأثير بعض العناصر الثقيلة في فعالية الأحياء المجهرية و نشاط إنزيم اليوريز في التربة

الملخص EN

Two laboratory experiments were conducted in soil and water science dept.

/ college of Agriculture at 2009 to study the effect of heavy metals (Ag, Cu and Hg ) on microbial and urease activity through different incubation periods stayed for two months .

A clay soil was used which brought from Al- ghumaij site in Thi-qar provens, south of Iraq.

The soil was treated by four levels of each Ag, Cu and Hg which were 0 , 60 , 120 and 180 Hg.g-1 soil .The results showed that the addition of heavy metals caused an inhibition in microbial activity by 34.41 , 44.07 and 33.01 % at the level 180 ^ig.g-1 soil by using the above metals respectively ; while the inhibition in the urease activity were 22.99 , 35.82 and 36.69 % by using the same levels .The inhibition in microbial and urease activity caused by heavy metals continued up to 60 days from incubation.