Abstract

Nitrogen balance in the rice growing flooded soils of Cauvery Delta as influenced by the soil types and sources and levels of N were studied. The volatilization and leaching losses were higher in the light textured Madukkur series compared to those of the heavy textured Kalathur and Padugai series. Application of urea super granule (USG) recorded the lowest volatilisation loss and the highest leaching loss irrespective of the soils. The total loss of N was reduced when the coated N sources (Lac coated uren, Neem coated urea and Coal tar coated urea) were used in light textured Madukkur series. The N balance in the heavy textured Kalathur and Padugai series were positive (+780 and +455 mg pot-1 respectively) and in the light textured Madukkur series, it was negative (-79 mg pot-1).

Keywords: N source, N losses, N balance, Rice soils