17 Journal of Cereal Research 11(1):17-22 Research Article Nitrogen top dressing just before irrigation improves wheat growth, productivity and nitrogen use effciency and proftability Subhash Chander Gill*, Ramesh Kumar Sharma, Subhash Chandra Tripathi, Rajender Singh Chhokar, Raj Pal Meena and Ankita Jha ICAR- Indian Institute of Wheat and Barley Research, Karnal, Haryana-132001 Article history Received: 07 Sep., 2018 Revised : 17 Dec., 2018 Accepted: 22 Dec., 2018 Citation *Corresponding author Email: sbhgill@yahoo.com, © Society for Advancement of Wheat and Barley Research Abstract A four year feld study was conducted from 2010-11 to 2013-14 at the research farm of ICAR-Indian Institute of Wheat and Barley Research, Karnal, Haryana to evaluate the infuence of timing and frequency of urea top dressing on wheat productivity. The 13 treatments consisted of three nitrogen levels (90, 120 and 150 kg N ha -1 ), two time of application (just before applying irrigations and about a week after irrigations when it was possible to walk in the feld) and two schedule of application (three equal splits as 1/3 rd basal, 1/3 rd at frst irrigation and 1/3 rd at second irrigation; and four equal splits as 1/4 th basal, 1/4 th at frst irrigation, 1/4 th at second irrigation and1/4 th at third irrigation) along with one absolute control. The study revealed that urea top dressed just before irrigation and nitrogen splitted in three equal doses led to better crop growth, yield attributes and yield of wheat leading to improved agronomic NUE (22.5-29.8 kg grain kg -1 applied N) than urea top dressed after irrigation and nitrogen splitting in four equal doses at all levels of nitrogen application (90-150 Kg ha -1 ). The highest wheat productivity was recorded with 150 kg N ha -1 applied in three splits with top dressing just before irrigation. Additional yield of 2.70-5.21q ha -1 (average 3.94 q ha -1 ) was produced when urea was applied just before irrigation as compared to urea top dressed after irrigatin. This yield gain was 5.93 to 10.83 percent (average 8.36 %). This practice gave additional beneft of Rs. 4680 to 9043 ha -1 (average Rs. 6843 ha -1 ). Keywords: Agronomic NUE, grain protein, N splitting, urea top dressing, proftability 1. Introduction Wheat (Triticum aestivum L.) is the second most important staple food crop of India after rice. It is cultivated on 29.58mha area with 99.7mt production having an average yield of 3371 kg ha -1 (4 th advance estimates from the Agricultural Statistics Division, Directorate of Economics and Statistics, Department of Agriculture, Cooperation and Farmers Welfare, GOI, New Delhi). In India’snorthern plains, spring wheat is cultivated with the use of moderate level of N i.e. 150 kg ha -1 (Coventry et al., 2011) and the fertilizer recommendation for wheat is also 150 kg N ha -1 (2-split schedule: 1/3 at sowing and 2/3 at the frst node stage or half at sowing and half at frst irrigation) and 60 kg P 2 O 5 ha -1 and 40 kg K 2 O ha -1 at sowing (Mishra et al., 2005; Srivastava et al., 2006). Most of the soils in Haryana and Punjab where wheat is grown in an irrigated double-cropping pattern, are defcient in N. In the rice–wheat rotation, farmers are applying more than the recommended N level (150 kgN ha -1 ). A survey by Singh et al.(2010) indicated that farmers’ in Haryana apply on an average 165.7 kg N ha -1 and 30 kg P 2 O 5 ha -1 to wheat with only 9.2% of the farmers used K-fertilizer. The current understanding is that a 2-split application of N fertiliser is suited to the slightly heavier soils of eastern Haryana where the rice–wheat system dominates and in the west and south-west regions that have lighter soils and where rice is not grown apply N in 3 splits. Application of 150 kgN ha -1 in three splits i.e. 1/3 basal at sowing, 1/3 after frst irrigation and 1/3 at spike initiation yielded Homepage: http://epubs.icar.org.in/ejournal/index.php/JWR Gill SC, RK Sharma, SC Tripathi, RS Chhokar, RP Meena and A Jha. 2019. Nitrogen top dressing just before irrigation improves wheat growth, productivity and nitrogen use effciency and proftability Journal of Cereal Research 11(1):17-22 doi. org/10.25174/2249-4065/2019/83006