Field experiments were conducted at Cropping Systems Research Centre, Karamana, Thiruvananthapuram, Kerala during summer/third crop/puncha season in 2007 and 2008 to find out the effect of nutrient sources under different management systems. The experiment was laid out in split plot design with four replications. The treatments consisted of four management systems viz., System of Rice Intensification SRI (M1), Integrated Crop Establishment Method (ICM) (M2), Package of practices (PoP) (M3) of Kerala Agricultural University and Conventional management practices (M4) in main plot. Nutrient sources viz., organic sources (S1), integrated nutrient sources (S2) and inorganic sources (S3) were the sub plot treatments.