Abstract:
Distribution of different zinc forms and its relationship with physico-chemical properties in three blocks
under red and lateritic soils of West Bengal were studied. Sequential extraction scheme was used to
fractionate Zn into Water Soluble and Exchangeable (WE), Organic bound (Org), Amorphous
sesquioxide (Amor), Crystalline Sesquioxide (Cry), Manganese bound (Mn) and Residual zinc (Res).
Results of the study indicated that the most of soils were sandy clay loam in texture with strong to
moderately acidic pH (4.35-6.94). The organic carbon content of these soils ranged from 0.25 to 0.76
percent. DTPA-zinc varied from 0.37 to 1.28 mg kg-1
. Total zinc was calculated as the sum of all the
pools and it varied in between 25.97 and 54.46 with an average of 39.51 mg kg-1
. The distribution of Zn
in the soils based on average concentrations was in the order of 25.49 mg kg-1 Res Zn (64.51%)> 5.05 mg
kg-1 Mn-Zn (12.7%) > 4.96 mg kg-1 Cry-Zn (12.5%)> 2.61 mg kg-1 Amor-Zn(6.6%)> 1.04 mg kg-1 Org Zn(2.6%) >0.48 mg Kg-1 WE-Zn (1.21%). Correlation analysis showed all the fractions were
significantly and negatively correlated with soil pH, while as a positive relation with organic carbon
(OC), DTPA-Zn and clay content. All the fractions were significantly and positively correlated among
themselves, indicating existence of dynamic equilibrium among the different pools of zinc.
