Increasing urea-N efficiency in transplanted lowland rice by urea solution band placement

Alternative N fertiliser management strategies are needed to increase N-use efficiency in wetland rice (Oryza sativa L.). In the wet season of 1993-1994, field experiments were conducted to evaluate the band placement of urea solution in comparison with broadcast prilled urea, neem-coated urea, or point-placement of urea super-granules. Both grain yield and N-use efficiency were higher with band placement of urea solution (50 or 100 kg N ha-1) compared to a conventional split application of prilled urea at 100 kg N ha-1. The total 15N recovery was 58.7 and 51.7% with band placement of urea solution at 50 and 100 kg N ha-1, respectively, compared with 47.8% for neem-coated urea and 28.5% for a conventional split application of prilled urea.