title: Nitrogen Fertilizer Management for Enhancing Crop Productivity and Nitrogen Use Efficiency in a Rice-Oilseed Rape Rotation System in China.
abstract: The use of efficient rates of nitrogen (N) fertilizer application is important with regard to increasing crop productivity and maintaining environmental sustainability. Rice-oilseed rape rotations are a mainstay of the economy and food security of China. Therefore, a field experiment was carried out during 2011-2013 in Honghu to identify the most appropriate N application rates for enhancing crop productivity and N use efficiency for rice (Oryza sativaL.)-oilseed rape (Brassica napusL.) rotations. Six N fertilizer treatments (RO1, RO2, RO3, RO4, RO5, and RO6) were laid out in a randomized complete block design with three replicates. ROxrepresented the N fertilizer application rates (kg ha-1) for rice and oilseed rape, respectively. Grain yields from plots receiving N fertilizer were significantly increased by 59-71% (rice) and 109-160% (oilseed rape) during the total rotation (2011-2013), as compared to RO1 (control; no application). Furthermore, a similar trend was observed for N accumulation, ranging from 88 to 125% and 134 to 200% in aerial parts of rice and oilseed rape, respectively. Nitrogen use efficiency (NUE) was significantly higher (38.5%) under RO2 and lower (34.2%) under RO6 while apparent N balance (ANB) was positively lowest under R05 (183.4 kg ha-1) followed by R02 (234.2 kg ha-1) and highest under R06 (344.5 kg ha-1) during the total rotation. The results of grain yield, NUE, and ANB indicated that the R02 rate of N application was superior. This information should help to develop a cost-effective and environment-friendly N management strategy for rice-oilseed rape rotation systems of central China.
authors.affiliation: 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, China.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Yousaf
authors.affiliation: 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, China.
authors.forename: Xiaokun
authors.initials: X
authors.lastname: Li
authors.affiliation: 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, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: 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, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Ren
authors.affiliation: 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, China.
authors.forename: Rihuan
authors.initials: R
authors.lastname: Cong
authors.affiliation: Department of Crop Cultivation and Crop Physiology, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China.
authors.forename: Syed Tahir
authors.initials: ST
authors.lastname: Ata-Ul-Karim
authors.affiliation: Department of Crop Cultivation and Crop Physiology, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China.
authors.forename: Shah
authors.initials: S
authors.lastname: Fahad
authors.affiliation: Department of Crop Cultivation and Crop Physiology, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China.
authors.forename: Adnan N
authors.initials: AN
authors.lastname: Shah
authors.affiliation: 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, China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Lu
keywords: apparent N balance; grain yield; nitrogen management; nitrogen use efficiency; rice-oilseed rape rotation