Distribution of micronutrients in arid zone soils of Punjab and their relation with soil properties

Abstract

Abstract Profile distribution was investigated for total and DTPA‐extractable Zn, Cu, Mn, and Fe in soils developed on three physiographic zones (alluvial terraces, interdunal areas, and sand dunes) in the arid zone of Punjab in northwest India. Total and DTPA‐extractable micronutrient cations were highest in soils of alluvial terraces followed by soils of interdunal areas and sand dunes. Irrespective of physiographic zone the soils did not show any pattern of depth distribution of DTPA‐extractable micronutrients. Total Zn and Mn showed accumulation in the B horizons, whereas Cu and Fe did not exhibit any specific pattern. Differences in organic carbon content and size fractions that were associated with changes in physiography had a strong influence on the micronutrient status of the soil. Based on linear coefficients of correlation, DTPA‐extractable micronutrients increased with an increase in organic carbon, cation exchange capacity, silt, and clay, and decreased with an increase in sand content, whereas Mn decreased with an increase in sand and calcium carbonate content. Total content of all micronutrients increased with an increase in silt and clay, whereas Zn and Fe increased with increase in organic carbon content. As physiography changed from alluvial terrace to sand dune, the available forms of micronutrients decreased. Analysis of surface soils revealed widespread deficiency of Zn and Fe, particularly in sand dune soils.