Nitrogen fertilizer is a major input in rice production, the optimum rate and also the application timing management to assure profitability and sustainability . This research indicated that N rates and timings had more influence growth parameter . Nitrogen application with small rate has significant effects on grain yield and yield components. Based on research proved that frequently applying fertilizer with small rate are requirement for increase high yield mostly on flowering stage. According to (Bluementol et al.2008) reported 6% increase in rice yield and 25% increase in grain protein due to N dressing at flowering stage.
The nitrogen uptake by rice use fertilized with liquid manure which is do not occur process N leaching thus will increase nutrient efficiency . According to (Harmit Singh Thind,2017) three times N rates will not give response compared to four times N rates because due to from low to high levels . This is because of higher N use efficiency and lower in N losses such as denitrification and leaching . In addition, different amount rate N fertilizer and time will give availability of nitrogen to paddy . According to (Fertilizer Management in Rice,2018) The time of application of split doses of fertilizer N varies can increase N use efficiency because critical growth stages of rice under different systems occur at different times.