Abstract
Experiments were conducted to study the forms of Co, and its relations with
some physical-chemical properties of some calcareous virgin soils of Kurdistan region.
Soil samples were taken at(0-00)cm depth from 11 different sites .The some chemical
and physical properties, and the amount of total and different forms of cobalt were
determined.
Total Co in soils varied widely from (01 to 74) mg.kg-1 soil .The statistical
analyses has shown that each of total carbonate, active lime, CEC, Fe, Mn oxides , clay
amount and organic matter has a significant role in determining of total Co .Water
soluble Co varied between (0001 to 00.0) mg.kg-1 and exchangeable Co extracted with
NaOAc ranged (000. – 004 5) mg.kg-1soil , whereas , exchangeable Co extracted with
acetic acid ranged ( 3000 to 1703.) mg.kg-1 soil .There were a positive significant
correlation between exchangeable Co and total Co, CEC, clay and organic matter
content , and a negative significant correlation with pH ,total carbonate and active lime.
Chelating Co extracted with (TPA+CaCl1+ TEA) ranged (0014 to 100.) mg.kg-
1 soil and it has a negative significant correlation with total carbonate, active lime, pH,
and a positive significant correlation with organic matter, Co bound to organic
substance and CEC.
Easily reducible Co which is bound to Fe and Mn ranged (0034 to 10005) mg.kg-1 soil
and has a high positive significant correlation with clay, organic matter, CEC ,water
soluble Co, and chelating Cobalt , and has a negative significant correlation with pH,
total carbonate, active lime .
Oxidisable Co which bound to organic substance ranged (7055 to 8. 50) mg.kg-1
soil and has a high negative significant correlation with clay, organic matter, chelating
Co, and positive significant correlation with pH, total carbonate and active lime.
Co bound to non-silicate metals ranged (1045 to 1001.) mg.kg-1 soil. These values
have a high negative significant correlation with clay, organic