| Breeding and applying of super rice varieties with high harvest index is an effective way to achieve high yield and high efficiency in rice production.However,rice yield is not only related to varieties,it is also affected by cultivation and management measures（such as nitrogen management）.Improper application of nitrogen fertilizer will not only affect the yield formation of rice,but also lead to a series of problems such as lower nitrogen use efficiency and plant lodging.However,there have been no reports about the effects of nitrogen managnement（nitrogen application rate and spilt nitrogen application ratio）on the yield formation and lodging resistance of super rice with high harvest index.Accordingly,this research choose super rice variety Guiliangyou 2 with high harvest index as material,set of two N application rate(N1=150 kg ha-1,N2=225 kg ha-1),and three Basal fertilizer:tiller fertilizer:panicle fertilizer（T1=6:3:1,T2=5:3:2 and T3=4:3:3）,at the same time set a treatment without nitrogen（N0）used for nitrogen fertilizer utilization rate calculation.This experiment with different nitrogen management was studied in Guiliangyou 2 on yield,production and transportation of dry matter,nitrogen utilization and lodging resistance,etc.The main results are as follows:（1）Both nitrogen application rate and split nitrogen application ratio had significant effects on the yield formation of Guiliangyou 2.The yield of N2T3 was 9.63 t ha-1,which was 10.06%and 7.96%higher than that of N1T1 and N1T3,respectively,and the difference was significant,because of the high crop growth rate,radiation use effeciency,SPAD value,net photosynthetic rate and dry matter accumulation.There were no significant differences in crop growth rate,radiation use efficiency,leaf area index,photosynthetic potential,SPAD value,net photosynthetic rate,dry matter accumulation and yield between N1T2,N2T1,N2T2 and N2T3 with the highest yield.Among them,N1T2 combination obtained the highest N harvest index（68.69%）,N agronomic use efficiency（13.83 g g-1）and N partial productivity（58.74g g-1）due to its high apparent output rate of stem matter and low N application.（2）The nitrogen application rate had a significant effect on the plant lodging index of Guiliangyou 2.N1 treatment was 20.00%lower than N2 treatment,and the difference reached a significant level.The split nitrogen application ratio had no significant effect on lodging index.In addition,the results of this study also showed that the lodging index was significantly positively correlated with the plant gravity center height,and negatively correlated with the internode bending moment and breaking moment.The gravity center height of N1 treatment was 48.38 cm,which was 3.78%lower than that of N2 treatment,and the difference was significant.The bending moment and breaking moment of N1 treatment were 2016.0g cm and 2161.7g cm,respectively,which were 10.26%and 21.26%higher than those of N2 treatment,respectively,and the differences were significant.In conclusion,under the conditions of this experiment,N1T2(i.e.,nitrogen application rate is 150 kg ha-1 and basal fertilizer:tiller fertilizer:panicle fertilizer is 5:3:2)is not only beneficial to the formation of high yield of Guiliangyou 2 super hybrid rice with high yield index,but also beneficial to improving its lodging resistance. |
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