| Abstract: | Two greenhouse experiments were conducted simultaneously to evaluate polymer-coated and common urea in upland rice production. The nitrogen (N) levels used for both the N sources were from 0 to 400 mg kg?1 of soil. Maximum grain yield was obtained with the addition of 167 mg N kg?1 polymer-coated urea and 238 mg N kg?1 common urea. Maximum value of other plant traits was obtained with N applied from 233 to 313 mg kg?1 depending on plant traits and N source. Nitrogen-use efficiency (NUE) decreased with increasing N rate in the two N sources. Based on results of growth, yield, and yield components, and NUE it can be concluded that the N sources were equally effective in upland rice production. Base saturation, pH, and exchangeable calcium (Ca) increased with increasing N rates while iron (Fe), manganese (Mn), and copper (Cu) contents decreased with the increasing N rates. |
