Distribution of zinc and its fractions in paddy growing soils of Upper Krishna command area of Karnataka

Abstract

An investigation was undertaken to characterize the distribution of zinc and zinc fractions in paddy soils of UKP command area. Twenty-six soil samples at two depths (0-15 and 15-30) were collected from paddy growing areas of Surpur (Shorapur) taluk. The results revealed the order of availability of zinc fractions in those soils was, water soluble plus exchangeable zinc < organically bound zinc < crystalline bound zinc < amorphous sesquioxide bound zinc < manganese oxide bound zinc < residual zinc. The correlation studies revealed that, water soluble plus exchangeable zinc and total zinc correlated negatively with pH and CaCO3 and positively with organic carbon and clay content. Organically bound zinc showed positive correlation with organic carbon content of soils. Manganese oxide bound zinc and amorphous sesquioxide bound zinc and crystalline sesquioxide bound zinc correlated positively with clay content. Residual zinc positively correlated with organic carbon and clay content of soils. The different forms of zinc present in Surpur taluk at surface and subsurface paddy soils were positively correlated.