A.K. Dash, B.K. Mishral, K.K. Bandyopadhyay and D. Jena
Abstract
A 2 mm sieved surface Sandy loam soil sample was packed in four PVC cylinders each of 0.14 m long and 0.086 m internal diameter to a bulk density of 1.5 Mg m-3.These four soil columns were saturated with 0.01 N CaSO, solution and surface applied Prilled Urea (0.043 g N), Nimin Coated Prilled Urea (0.043 g N), Nimin Coated Prilled Urea (0.054 g N) and No-N Control were displaced with same saturating solution for 356 h.The leachate fractions were analyzed for NH2-N, N1-14+-N and NO;-N. Leaching of NH2-N was more from Nimin Coated Prilled Urea (NCPU) than Prilled Urea (PU) alone.The leaching of NH2 N was also increased as the nitrogen content in soil column was increased. But, the leaching of NH4+-N was maximum (28.4 %) in case of surfaced applied PU, intermediate (27.1 %) with lower dose of NCPU and lowest (15.29%) with higher dose of NCPU. On the other hand, leaching of NO3- - N was negligible either from PU or NCPU. The rate constant for urea hydrolysis was computed to be more (0.08 h1) in case of PU and was less (0.055 to 0.069 ft') in case of NCPU.The velocity of NH2-N was faster than NH4- N in different soil columns.