Changes in Zinc Concentration as Influenced by Sesquioxide Under Different Moisture Regimes in Acidic Rice Soils of Eastern India

Abstract

The availability of zinc (Zn) in soils is influenced by pH, organic matter content, clay particles and sesquioxides. We conducted laboratory incubation experiments on a rice-growing soil (Alfisol) to determine the effect of sesquioxide on zinc availability under different moisture regimes. Three different graded doses of zinc (0, 5 and 10 mg Zn/kg) were applied to soil containing sesquioxide and without sesquioxide under saturated and waterlogged conditions. The extractable zinc under 0.1 N HCl and 0.005 M DTPA was highest in the soil without sesquioxide and followed the order as: 0.1 N HCl-extractable Zn > 0.005 M DTPA. During the 35 days of incubation, highest values of 0.1 N HCl-extractable Zn and 0.005 M DTPA-extractable Zn were recorded in soil maintained at saturated compared with waterlogged conditions. The zinc availability in soil was reduced by 53 and 20% in sesquioxide-free soil and sesquioxide-containing soil, respectively, irrespective of zinc extractants. Higher dose of applied Zn resulted in a greater reduction in the Zn availability and indicated for split application of Zn to enhance the Zn supplying power of soil to greater extent.