INTERNATIONAL JOURNAL OF AGRICULTURE & BIOLOGY ISSN Print: 1560–8530; ISSN Online: 1814–9596 16–285/2016/18–6–1137–1142 DOI: 10.17957/IJAB/15.0217 http://www.fspublishers.org Full Length Article To cite this paper: Yousaf, M., X. Li, T. Ren, R, Cong, S.T. Ata-Ul Karim, A.N. Shah, M.J. Khan, Z. Zhang, S. Fahad and J. Lu, 2016. Response of nitrogen, phosphorus and potassium fertilization on productivity and quality of winter rapeseed in central China. Int. J. Agric. Biol., 16: 1137‒1142 Response of Nitrogen, Phosphorus and Potassium Fertilization on Productivity and Quality of Winter Rapeseed in Central China Muhammad Yousaf 1 , Xiaokun Li 1 , Tao Ren 1 , Rihuan Cong 1 , Syed Tahir Ata-Ul-Karim 2 , Adnan Noor Shah 3 , M. Jamil Khan 4 , Zhi Zhang 1 , Shah Fahad 3 and Jianwei Lu 1* 1 Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture; College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China 2 National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, P. R. China 3 College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China 4 Department of Soil & Environmental Sciences, Gomal University, DI Khan, 29050, KPK, Pakistan * For correspondence: lunm@mail.hzau.edu.cn Abstract Winter rapeseed (Brassica napus L.) is a dominant oilseed crop and has become an alternate crop both for edible oil production and energy agriculture. This study was conducted to find out the response of nitrogen (N), phosphorus (P) and potassium (K) fertilizer combinations on yield, oil and protein contents in oilseed rape crop. Four fertilizer treatments of N, P and K fertilizers (NPK, NP, NK, and PK) were applied according to the local recommendations at three different sites in Hubei province, during the year 2012-2013. Rapeseed yield was significantly increased by 61-72% under NPK fertilization as compared to PK across study sites. Yield responses to fertilization were ranked as NPK>NP>NK>PK, illustrating that N was the most limiting nutrient in rapeseed productivity following P and K. Oil and protein yields were significantly affected to applied N, P, and K fertilizers. Among all combinations, NPK combination performed best. Oil and protein contents along with other fatty acids (palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid) were not influenced significantly by the application of P and K fertilizer. By increasing the amounts of N fertilizer application, oil contents of rapeseed reduced and protein contents increased consistently. These results suggest that NPK combination is more productive as compared to the other combinations. © 2016 Friends Science Publishers Keywords: Winter rapeseed; NPK; Yield; Protein yield; Oil content Introduction Oilseed rape (Brassica napus L.) is an essential agricultural crop generally grown for oil and biofuel generation. Rapeseed oil is ordinarily utilized in human diets on account of its great nutritional quality with a high proportion of unsaturated fatty acids and fair-minded fatty-acid composition (Rehman et al., 2013; Wang et al., 2014). After extraction, remaining rapeseed meal can be used as an organic fertilizer to the cropland or as a source of animal feed (Gao et al., 2010). The nutritional nature of these products is of prime significance, because of their immediate and circuitous effects on human health. Additionally, rapeseed oil is developing consideration as an imperative option for bioenergy asset, because of the deficiency and unpredictability of the worldwide petroleum supply (Högy et al., 2010). The rapeseed is broadly planted on 34.3 million ha around the globe, with almost 22% of the planting ranges situated in China (FAO, 2013). Among numerous other parameters, the nutritional values of the crop are thought to be most imperative element. N, P, and K are considered to be critical being the crucial part of harvest yield and nutritious values of the oilseed rape yield. Nitrogen is the most important macro- element required for seed oil (Colnenne et al., 1998) and it is suggested that oilseed rape has a higher basic N demand for biomass development than wheat. The suitable quantity of N fertilizer is requisite for optimal economic yield and oil generation (Mason and Brennan, 1998). Smith et al. (1988) reported that high amount of N fertilizer reduced the oil contents but enhanced the protein contents in canola and found a negative co-relation between oil concentration and protein contents. Phosphorus (P) is an imperative nutrition for plant development as concerned with photosynthesis, cellular energy transfer, and respiration. Regardless of the way that canola demands more phosphorus than grain crops for perfect yields, it might need minor levels of P fertilizers, as it is extraordinarily suitable for utilizing both applied and soil P