Srivastava, AjayaVineet Kumar2018-09-062018-09-062015-06http://krishikosh.egranth.ac.in/handle/1/5810072155An investigation was carried out to study the distribution of available macronutrients (N, P, K and S) and some micronutrient cations (Fe, Mn, Cu and Zn), their relationship with some physical properties of soil and the evaluation of availability indices for Nitrogen, Phosphorus and Potassium in soils of different blocks of district Udham Singh Nagar (Uttarakhand).The soils of the district were found sufficient in Phosphorus, Potassium and Sulphur but low in available Nitrogen content and the soil samples were sufficient in micronutrient cations. Different methods of analysis of soil were employed, to know the best method among them, for availability of N, P, and K. Available Nitrogen was analyzed by Organic carbon and alkaline KMnO4-N methods, available Phosphorus by Olsen’s P, AB-DTPA P, Mehlich-1 P and Bray & Kurtz P and available Potassium by Ammonium acetate K, AB-DTPA K, Mehlich-1 K and Modified morgan K for the soil samples of district Udham Singh Nagar. Highest suitability was obtained with Alk. KMnO4 (R2 = 0.437), Olsen’s (R2 = 0.501) and AB-DTPA (R2 = 0.603) method for Nitrogen, Phosphorus and Potassium, respectively. In general the macronutrients were correlated significantly and negatively with pH and positively with organic carbon and the DTPA-extractable micronutrient cations were positively and significantly correlated with organic carbon and clay content but negatively with pH of the soil. The values of the organic carbon, Alkaline KMnO4 extractable N, Olsen’s P and neutral normal Ammonium Acetate extractable K in the Udham Singh Nagar district ranged between 0.13-1.64 per cent, 125.44-338.68 kg N ha-1, 7.34-76.70 kg P ha-1 and 66.08-271.04 kg K ha-1, respectively and the values of DTPA-extractable Fe, Mn, Cu and Zn in soil samples of the district were ranged from 12.42-54.06, 0.96-22.06, 0.26-3.79 and 0.59-5.04 ppm respectively. Findings from present study can successfully be utilized for the larger parts of Tarai region of Uttarakhand as effective guide for efficient and balanced fertilizer recommendations.enThesis