1
2
*Corresponding author: hathokpam@yahoo.in
Profile distribution of DTPA-extractable micronutrient cations (Zn, Cu, Fe and Mn) and their relationship with various soil properties were studied in eighteen profiles of citrus orchard of Ukhrul district of Manipur. The content of DTPA-extractable Zn, Cu, Fe and Mn were higher in surface horizons and decreased with depth in most of the profiles and ranged from 0.08 to 0.76, 0.01 to 0.34, 8.0 to 54.0 and 1.6 to 20.4 mg Kg−1, respectively. Surface horizons contain sufficient amount of DTPA-extractable micronutrient cations except Zn. Distribution of Mn was influenced positively with EC in the first (0–20 cm) and second layer (20–40 cm), Cu was influenced inversely by organic carbon and positively by EC, Zn was influenced positively with CEC and Fe was influenced by clay content of the soils. Multiple regression analysis indicated that DTPA-extractable Zn, Cu, Fe and Mn were influenced by CEC, EC, clay and EC to the level of 0.25, 0.63, 0.25 and 0.41, respectively. However, only clay and EC contributed significantly towards these nutrient cations.
• Deficiency of micronutrients has become a major constraint to productivity and sustainability in many Indian soils.
• The knowledge of profile distribution of micronutrient cations is important as roots of many plants go beyond the surface layer and thus draw a part of the nutrient requirement from the subsurface layers of the soils.
• Same per cent of the studied soil samples fell in deficient categories.
• Out of the eighteen profiles, DTPA-extractable Cu content in the three surface profiles were found in adequate range.
• All the soils had suffident amounts of available Fe considering 4.5 mg kg−1 as critical limit.
• Considering the critical limit of 1.0 mg kg−1, b the soils were well above the critical limits.
DTPA, micronutrient cations, citrus orchard, profile, multiple regression analysis
