Effects of nitrogen management on dry matter accumulation and nitrogen use efficiency of Guiliangyou 2.

Objective Super rice Guiliangyou 2 was used to study the effects of nitrogen (N) management on dry matter (DM) accumulation and N-use efficiency in Guangxi Province. Method Field trials with five N treatments three nitrogen rates: 0 (N0), 210 (N1) and 255 (N 2 ) kg/ha; two N fertilizer distribution ratio: 5:3:2 (F1) and 4:3:3 (F2) for basal, tillering and heading dressings, respectively were conducted. ResultThe results showed that DM accumulation of Guiliangyou 2 at different stages significantly increased due to nitrogen fertilizing. Thus, compared to other treatments, F2N1 and F2N1 treatments raised DM increment after heading and its contribution to yield. The total nitrogen uptake of Guiliangyou 2 increased with the increasing applied N, and F2 treatment was beneficial to improve the absorption of nitrogen from the soil and N fertilizer. With the same N fertilizer rate, a certain increase of NPFP, NAE and NRE in F2 treatments were found compared with F1. Despite F2N2 treatment obtaining the highest yield, there was no significant difference between F2N1 and F2N2 , NPFP, NAE and NRE of F2N1 were the highest. Conclusion F2N1 treatment, with N rate of 210 kg/ha and N fertilizer distribution ratio of 4:3:3 for basal, tillering and heading dressings, could obtain high yield with high N-use efficiency in the production of Guiliangyou 2 sown in late season. The yield of F2N1 treatment was 8170.2 kg/ha. NPFP, NAE and NRE were 38.9 kg/kg, 12.6 kg/kg and 41.5%, respectively.