Improving Yield and Nitrogen Use Efficiency Using Polymer Coated Urea in Two Crop Establishment Methods of Rice (Oryza sativa L.) Under Vertisol (Typic Pellustert)

Abstract

Polymer coated urea (PCU) was evaluated for its efficiency under two rice establishment methods [transplanting method (TP) and direct - seeded rice (DSR)] during two crop seasons (rabi, dry season and kharif, wet season). The results indicated that split application of PCU @ 75 and 100% recommended dose of nitrogen (RDN) were at par and resulted in significantly higher yields (46 and 49%) than normal urea in splits, respectively, during rabi 2015–2016 under transplanting method. During kharif - 2016 under transplanting method, grain yield was maximum with 100% RDN from PCU single dose (5.13 t ha−1) which was on par to 100% PCU in 3 splits (4.62 t ha−1) and 75% PCU (4.80 t ha−1) as a basal dose. In DSR, significantly higher grain yield was recorded in 100% RDN supplied through PCU as basal dose (6.16 t ha−1). The maximum nitrogen use efficiency indices were observed in 75% PCU (split) followed by 100% PCU (Split) in rabi - 2015–2016 but in the case of kharif - 2016, basal application of 100% PCU found to be superior followed by 75% PCU. Thus, PCU proved its efficiency by saving 25% of N in transplanted rice in both wet and dry seasons and by considerable labour saving due to single basal application in case of transplanting as well as DSR in the wet season.