PRAKASH, S SYOGESH, M R2016-11-292016-11-2941138Th-10329http://krishikosh.egranth.ac.in/handle/1/87998An investigation was carried out to understand the organic carbon distribution pattern and short term temporal changes in SOC fractions in paddy fields of Sulekere Command Area, Mandya district. For characterization 155 surface soil samples were collected from paddy fields covering the entire command area before pudling, while for understanding the changes in organic carbon fractions samples were collected in the selected locations at panicle initiation and after harvest of paddy. Soil characterization revealed that soils were neutral to slightly alkaline in reaction with low soluble salts. Soils are low to medium in available N, P and K status and sufficient in Ca, Mg and micronutrients. The organic carbon content indicated that 12.90, 10.96 and 74.83 % of the samples were low, medium and high in SOC status. Water soluble carbon content increased slightly towards panicle initiation stage and stabilized to initial level at harvest of crop. MBC and MBN were decreased slightly from initial stage up to harvest stages. Whereas LFC was slightly lower in the initial samples but it was higher at harvest stage. The Coefficient of variance (%) for pH and available N was low while EC and available K, Ca, Mg and S are moderate and SOC and DTPA extractable micronutrients had highest variability. The range, a semivariogram parameter indicates spatial dependence varied from 53.19 m for Cu to 329.47 m for Mg in North Nala. Whereas it was 30.12 m for SOC and 18775.65 m for available K in South Nala.enThesis