Open Access Library Journal How to cite this paper: Khatun, A., Sultana, H., Bhuiya, Md.S.U. and Saleque, Md.A. (2015) Nitrogen Use Efficiency of Low Land Rice as Affected by Organic and Chemical Sources. Open Access Library Journal, 2: e1327. http://dx.doi.org/10.4236/oalib.1101327 Nitrogen Use Efficiency of Low Land Rice as Affected by Organic and Chemical Sources Amina Khatun 1* , Hasina Sultana 1 , Md. Sultan Uddin Bhuiya 2 , Md. Abu Saleque 3 1 Rice Farming Systems Division, Bangladesh Rice Research Institute, Gazipur, Bangladesh 2 Department of Agronomy, Bangladesh Agricultural University, Mymensingh, Bangaladesh 3 Advanced Studies & Research, Bangladesh Rice Research Institute, Gazipur, Bangladesh Email: * aminabrri@gmail.com Received 6 February 2015; accepted 21 February 2015; published 25 February 2015 Copyright © 2015 by authors and OALib. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Given the increasing dairy and poultry industries, cowdung (CD) and poultry manure (PM) might become alternative sources of nitrogen (N) for rice production in South Asia. A field experiment was conducted during dry season (November-April) in Gazipur, Bangladesh. The experiment aimed to evaluate N use efficiency (NUE) in rice under varying sources of N application. Six treatments—1) N-control; 2) optimum dose of nitrogen (164 kg N ha −1 ) from urea; 3) 50% N from urea and 50% N from CD; 4) 50% N from urea and 50% N from PM; 5) 100% N from CD; and 6) 100% N from PM— were compared. Two mega varieties—BRRI dhan28 and BRRI dhan29—were used as test crops. In BRRI dhan28, the urea treatment had the highest agronomic use efficiency (AUE), utilization effi- ciency (UE) and partial factor productivity (PFP) followed by urea + PM treatment and absolute PM treatment. In BRRI dhan29, the urea + PM treatment had the highest AUE followed by absolute urea treatment while the urea + PM treatment gave the highest UE and PFP followed by urea treat- ment and urea + CD treatment. The absolute PM treatment gave the highest physiological efficien- cy (PE) followed by absolute urea treatment in BRRI dhan28. In BRRI dhan29, the absolute PM treatment had the highest PE followed by urea treatment and urea + PM treatment. The absolute PM treatment had the highest agro physiological efficiency (APE) both in BRRI dhan28 and BRRI dhan29. Based on this finding, it is concluded that the practice of integrated use of organic and chemical fertilizer has the scope to reduce chemical fertilizer and also contribute to increasing ni- trogen use efficiency. Keywords Rice, Cowdung, Poultry Manure, Urea, N Use Efficiency Subject Areas: Agricultural Science * Corresponding author.