Utilization Advantages of Controlled Release Nitrogen Fertilizer on Paddy Rice Cultivation

Abstract

Labor-saving for fertilization has been strongly desired due to the shortage in labor and increasing scale of farming for rice cultivation. In order to clear these problems, the effect of application of controlled release nitrogen fertilizer (CRNF) on the different styles of paddy rice cultivation was investigated in southwestern Japan. Yield of transplanted rice grown by a single basal application of fertilizer consisting of 30% to 70% of sigmoid CRNF-100 was approximately equal to that grown by split application of ammonium sulfate under the same amount of nitrogen applied. In direct sowing cultivation under dry and flooded condition, rice yield was elevated by using nitrogen fertilizer consisting of 85% to 100% of CRNF. Approximately 30% of nitrogen applied was reduced in a single basal application with fertilizer consisting of 100% of CRNF nitrogen compared with that in split application with ammonium sulfate. Labor for nitrogen topdressing was completely saved by utilizing a single basal application with CRNF. The utilization of nitrogen fertilizer consisting of CRNF was also thought to be preservative to the environment.