Fate and recovery efficiency of controlled release nitrogen fertilizer in flooding paddy soil

Fate and recovery efficiency of (15N) labelled controlled release nitrogen fertilizer (CRNF) in flooded paddy soil were studied using lysimeter apparatus, microplot and field experiment. The results showed that application of CRNF, the losses of the ammonia volatilization, nitrogen leaching and nitrification-denitrification were greatly reduce. The quantity of ammonia volatilization and nitrogen leaching losses were reduced by 54.0% and 32.5% in CRNF treatment than in urea. Losses of nitrification-denitrification made up 34.5% of N applied in urea treatment, and only 2.0% of N applied in CRNF treatment. Percent of fertilizer N remained in the 0-80 cm soil layer was similar in both CRNF and urea treatments. The N recovery efficiency of one time application of CRNF averaged 65.6%, which was higher than 32.2 percent point than that of applying urea (basal and top dressing) and the CRNF gave better agronomic efficiency of N than urea.