DTPA-EXTRACTABLE ZN, CU, MN AND FE IN TRANS-GANGETIC PLAINS OF NORTHERN INDIA

Samples of surface soil, covering Trans-Gangetic Plains of northern In dia, were analysed for DTPA-extractable micronutrient cations and soil properties. The soils were alkaline in reaction with low salt content and low to medium in organic carbon content. These soils were somewha t calcareous in nature and loamy sand to sandy loam in texture. Consid erable variability in the contents of different micronutrients was obs erved, however, mean value for available Zn, Cu, Mn and Fe were 0.37, 0.87, 7.11 and 4.91 ppm, respectively. Majority of the soils were defi cient in Zn, marginal in Fe and sufficient in Cu and Mn. Available Zn, Cu, Mn and Fe were significantly and negatively correlated with pH an d positively with orgqnic carbon. The multiple regression equations re vealed 7, 23, 3 and 14% variations in available Zn, Cu, Mn and Fe, res pectively, were accounted for by the combined effect of pH, EC, CaCO3 and organic carbon contents. Organic carbon/organic matter was found t o be the most effective soil parameter affecting the status of micronu trients in the soils.