Effects Of Application Of Nitrogen Fertilizer On Population Growth, Yield And Quality Of Machincal-transplanting Rice With Long-aged Seedlings

Effects of different nitrogen applying amount A(75,150,225 kg/hm~2) and assigning proportion of nitrogen fertilizer B applying basic N tillering N and panicle N as 10:0:0,7: 3:0,6:0:4 and 4:3:3 on yield and grain quality of Machine-transplanted aged rice were studied,in taking the treatment without applying nitrogen as CK by taking hybrid rice Gang you 906 as material.The main results showed as follows:1.Increasing nitrogen applying amount accelerated the happening of tillers.Moreover, with the increasing of the amount of nitrogen applied,the leaf area and SPAD value of flag leaf enhanced,the leaf area index(LAI),specific leaf area(SLA),leaf area ratio(LAR), and leaf area duration(LAD) improved obviously,and it was highest when amount of N applied was 150 kg/hm~2,but the increasing extent of the ratio of efficient leaf area took on falling trend when amount of N applied was beyond 150kg/hm~2.they were all higher when applying N as 6:0:4 and 4:3:3 at late growth stage.2.With the increasing of amount of nitrogen applied,amount of dry matter accumulated at every growth stage increased,and CGR also improved;the percentage of transformation and output to leaf increased,that transformation and output to stem and panicle declined.As far as the ratio of matter outputting and translating of leaf and stem was concerned,the two assigning proportions which applying N as 10:0:0 and 7:3:0 was separately higher than the other two proportions which applying N as 6:0:4 and 4:3:3, With the increasing of amount of nitrogen applied,the percentage of dry matter distributed to leaf increased,that distributed to stem and panicle declined.3.Nitrogen is the indispensable nutrient to rice production.Increasing nitrogen applying amount,improved N-content of leaf and stem,and increased the amount of N leaving in straw at maturing stage(MS),reduced the amount of N leaving in panicle.With the increasing of nitrogen applying amount,total N accumulated(TNA) at every stage improved notably,but N production efficiency and NHI,NDMPE,NGPE,NAE reduced.TNA was highest when applying N as 6:0:4 in amount of N applied was 75 kg/hm~2 and 150 kg/hm~2,but when amount of N applied was 225kg/hm~2,TNA was highest in applying of N as 4:3:3 Among the four assigning proportions of nitrogen fertilizer,NHI,NAE and NTE of which applying N as 6:0:4 and 4:3:3 were all higher than which applying N as 10:0: 0and 7:0:3 but NGPE and NDMPE value were opposite.4.Yield varied under different N application With the increasing of nitrogen applying amount yield improved,and it was highest when amount of N applied was 75 and 150 kg/hm~2,Among four different assigning proportions of nitrogen fertilizer,the yield of which applying N as 6:0:4 was highest of all.but when amount of N applied was 225 kg/hm~2,yield was highest in applying of N as 4:3:3 Increasing nitrogen applying amount affected the component of yield too,the number of effective panicles improved obviously, the seed setting rate descend,and the number of seed per panicle improved in some scope, but at high N level it declined,among the four assigning proportions of nitrogen fertilizer, PTP,FG,NGPP and KGW of which applying N as 6:0:4 and 4:3:3 were all higher than which applying N as 10:0:0 and 7:3:0.5.Increasing the nitrogen applying amount properly,in certain range,was good for improving nutrient quality,machining quality and cooking quality.With the increasing of amount of nitrogen applied,the character of RVA profile of rice flour varied,peak viscosity, final viscosity,Breakdown,pasting temperature and setback improved,among the four assigning proportions of nitrogen fertilizer,peak viscosity,pasting temperature and breakdown value of which applying N as 7:0:3 and 4:3:3 were all higher than which applying N as 10:0:0,but chalky rice ratio,chalkiness and setback value were opposite.6.Changes of N uptake and utilization under different N application had an important influence on grain yield and quality.Chalky rice ratio,chalkiness and filled grain reduced with the increasing of N accumulation,the correlative coefficient between NGPE,NHI,NAE and NDMPE was significant at 0.01 levels,the correlative coefficient between brown rice,head rice,EP and NGPP was significant at 0.05 levels.There was negative correlation between NGPE,NHI,NDMPE,NAE and NTE.