稻茬小麦公顷产量9000 kg群体氮素积累、分配与利用特性

摘要

Nitrogen (N) is one of the essential nutrients for wheat production.It is very important to figure out what are the definite characteristics of N accumulation,distribution and utilization in different yield level populations,which is much theoretical and practical meaning to agricultural production.In this study,these characteristics of wheat population at yield level of 9000 kg/ha (LV.9000) were studied by agronomic management on the medium-gluten wheat,Yangmai 20 (Triticum aestivum L.),grown in rice-wheat rotation.The field experiments were performed at 32 combinations of two planting densities (150 × 104 and 225 × 104/ha)and different N managements,including N amount (210 and 262.5 kg/ha),the ratio of basis:tillering:elongation:late topdressing of N (3 ∶ 1∶ 3∶ 3 and 5 ∶ 1 ∶ 2 ∶ 2),and N topdressing stage (flag leaves stage,booting stage,heading stage and anthesis).The results show that the LV.9000 N accumulation amounts (NAA) at stages from the elongation to the anthesis,at the anthesis and at the maturity are 104-117,197-205 and 234-251 kg/ha,respectively,which are significantly higher than those of other populations.The NAAs in leaves,stems and spikes at the anthesis and in grain at the maturity are respectively significant linear positive correlation with the grain yield,and are 89-91,74-83,32-33 and 177-188 kg/ha under the LV.9000.The N translocation amount (NTA) from vegetative organ at anthesis to grain is significantly linear positive correlation with grain yield.The LV.9000 NTAs from leaves,stems,and raches and hulls at the thesis to grain are 65-73,53-54 and 16-20 kg/ha,separately.For the LV.9000 in rice-wheat rotation,the N amount to produce 100 kg of grain,N use efficiency and N harvest index are 2.9-3.0 kg,32.9-34.5 kg/kg and 0.73-0.77,respectively.%在稻-麦两熟制条件下,以扬麦20为材料,通过基本苗和氮素运筹(氮肥施用量、施用时期和比例)调控建立不同产量水平群体,研究稻茬小麦籽粒产量高于9000 kg/hm2群体的氮素积累、分配与利用特性.结果表明,稻茬小麦籽粒产量9000 kg/hm2以上群体拔节期至开花期、开花期及成熟期氮素积累量分别在N 104～117 kg/hm2、197～205 kg/hm2、234～251 kg/hm2,极显著高于籽粒产量9000 kg/hm2以下群体.稻茬小麦不同群体开花期叶片、茎鞘、穗及成熟期籽粒氮素积累量与籽粒产量均呈极显著线性正相关,氮素积累量分别为N 89～91 kg/hm2、74～83 kg/hm2、32～33 kg/hm2、177～188 kg/hm2,有利于实现籽粒产量9000 kg/hm2.花后群体营养器官氮素转运量与籽粒产量均呈极显著线性正相关,叶片、茎鞘及穗轴+颖壳的氮素转运量分别为N 65～73 kg/hm2、53～54 kg/hm2、16～20 kg/hm2,有利于实现籽粒产量9000 kg/hm2.稻茬小麦籽粒产量9000 kg/hm2以上群体100kg籽粒吸氮量为N 2.9～3.0 kg,氮素利用效率32.9～34.5 kg/kg,氮收获指数0.73～0.77.