Nitrogen-15 balance in transplanted and direct-seeded flooded rice as affected by different methods of urea application |
| |
| Authors: | H F Schnier M Dingkuhn S K De Datta E P Marqueses J E Faronilo |
| |
| Institution: | (1) Agronomy Department, The International Rice Research Institute, P.O. Box 933, Manila, Philippines |
| |
| Abstract: | Summary Alternative N-fertilizer management practices are needed to increase productivity and the N-use efficiency of flooded rice (Oryza sativa L.). In the 1987 dry season, a field study using 15N-labeled urea evaluated the effect of the time and method of fertilizer-N application on grain yield and N-use efficiency in transplanted and direct-seeded flooded rice. Conventional fertilizer application (broadcasting and incorporation) was compared with band placement of liquid urea and point placement of urea supergranules. With band or point placement, the grain yields were significantly greater, and the partial pressure of NH3 (pNH3) in the floodwater was significantly reduced. In the transplanted rice, conventional fertilizer-N application gave a 64% total 15N recovery and 38% crop (grain and straw) recovery. Band placement of liquid urea N resulted in 92% total and 73% crop recovery. In the direct-seeded flooded rice, a conventional N application gave 72% total and 42% crop recovery; band placement, 98% total and 73% crop recovery; and urea supergranule point placement, 97% total and 75% crop recovery.Dedicated to Prof. Dr. K. Mengel, Giessen, FRG, in honor of his 60th birthday. |
| |
| Keywords: | Band placement 15N recovery Fertilizer N use Immobilization NH3 volatilization Wetland rice Urea Oryza sativa L |
| 本文献已被 SpringerLink 等数据库收录！ |
|
