Effect Of Nitrogen Application And Irrigation Methods On Nitrogen Accumulation,Yield And Quality In Longdao 21

Water and nitrogen play an important role in high yield and quality of rice.The exploring the amount of reasonable nitrogen fertilizer and water-saving irrigation technology of rice are of far-reaching significance for ensuring that the sustainable development of agricultural.In this study,the Longdao 21 is the experimental material.It adopts split-splitplot design,the application rate of nitrogen fertilizer is the main area and the proportion ratio of nitrogen fertilizer is the split area,the irrigation method is the split-split area.Three nitrogen application levels are set respectively low nitrogen fertilizer(N1:120kg/hm~2)、nitrogen fertilizer(N2:140kg/hm~2)、high nitrogen fertilizer(N3:160kg/hm~2).Nitrogen fertilizer application ratio is set at 3 levels respectively F1(base fertilizer:tillering fertilizer:spike fertilizer=4:4:2);F2(base fertilizer:tillering fertilizer:spike fertilizer=4:5:1;F3(base fertilizer:tillering fertilizer:spike fertilizer:granulated fertilizer=4:3:2:1).The second level of irrigation is water-saving irrigation(T1:400m~3/mu)and conventional irrigation(T2:500m~3/mu).The effects of nitrogen application and irrigation methods on nitrogen accumulation,yield and quality of japonica rice are studied in order to lay a theoretical foundation and technical support for the formulation of rational irrigation and nitrogen application management mode.Research indicates:(1)Plant height panicle length and effective panicles increased significantly with increasing nitrogen application,seed setting rate decreased significantly,the number of primary branches and grains,the number of secondary branches and grains,spikelets per pan and yield increased first but then decreased,and N2 is significantly higher than in the N1 and N3 treatments.There is no significant difference between the nitrogen application rates of 1,000-grain weights.Under the treatment of low,medium and high nitrogen fertilizer,the interaction with F3T1 treatment could increase plant height and panicle length.The interaction between low nitrogen fertilizer and F3T1 treatment,and the interaction between medium and high nitrogen fertilizer and F2T1 treatment can significantly increase the number of primary branches,the number of grains and yield of primary branches.For N3F3T1,plant height and panicle length are the highest,The number of primary branches and grains,the number of secondary branches and grains,yield of N2F2T1 are significantly higher than those of the other treatment combinations.(2)After full heading stage,dry matter weight and nitrogen accumulation of stem and leaf decreased gradually,while dry matter weight and nitrogen accumulation of panicle increased gradually.At maturity,with the increases of nitrogen application rate,dry matter weight of stem and leaf increased significantly.Dry matter weight of panicle increased first and then decreased.Nitrogen accumulation in stems,leaves,and panicles increased with increasing nitrogen application.Stem dry matter weight of N3F3T1 is higher than all treatments,leaf dry matter weight of N3F2T1 is significantly higher than all treatments except N3F3T1,and panicle dry matter weight of N2F2T1 is significantly higher than all other treatments.The interaction between low nitrogen fertilizer and F3T1 treatment,and the interaction between medium and high nitrogen fertilizer and F2T1 treatment increased the nitrogen accumulation of stem,leaf and ear.N3F2T1 have the highest nitrogen accumulation in stems,leaves,and panicles.The NRE、NAE and PFPN of N2F2T1 treatment combination was the highest.(3)The indexes of the processing quality of Longdao 21 first increased and then decreased with the increase of nitrogen application,N2 treatment was significantly higher than that of N1 and N3 treatment,the content of appearance quality and four protein components increased significantly with the increase of nitrogen application,and the content of amylose decreased significantly with the increase of nitrogen application.Under the treatment of low,medium and high nitrogen fertilizer,interaction with F3T1 treatment can improve the processing quality indexes,and the processing quality indicators of the N2F3T1 treatment combination is the highest.The chalk whiteness of broken rice in the N1F1T2 treatment combination was significantly lower than that of other treatment combinations,and the whiteness of polished rice chalk was significantly lower than that of other treatment combinations except N1F2T2.The N3F3T2 treatment had the highest content of each protein component.The amylose content of grains in the N2F3T1 treatment combination was significantly lower than that of the other treatment combinations except N2F3T2.N2F3T1 treatment group have the highest taste value of 88 points.(4)The combination of N2F3T1 treatment is the best combination of nitrogen application and irrigation cultivation mode screened in this study.