【摘要】 以两系杂交稻两优培九为试材,研究不同N肥用量(纯N 0、112.5、225.0、337.5 kg/hm2)和栽插密度(22.5×104、27.0×104、31.5×104穴/hm2)对产量形成及N素吸收利用的影响。结果表明:(1)栽插密度对结实率和千粒重影响较小,对单位面积穗数和每穗粒数影响较大,在22.5×104~31.5×104穴/hm2的密度范围内,穗数与每穗粒数之间具有良好的互补性,因而产量差异未达显著水平。(2)N肥用量对每穗粒数影响较小,对穗数、结实率和千粒重影响较大,纯N用量为337.5 kg/hm2时,增穗作用不显著,反而极显著降低结实率和千粒重,导致减产。(3)稻株吸N量随供N水平的提高而增加,但植株含N率和N素累积量过高不利于叶鞘茎中的N素向穗部运转,降低籽粒N素积累量,导致结实率和千粒重显著下降而减产。(4)在中等肥力土壤上,施纯N 225.0 kg/hm2,栽插密度22.5×104穴/hm2,高峰苗控制在500.0万/hm2左右,有利于两优培九抽穗前茎鞘叶N素积累和抽穗后向穗部运转,能较好地协调穗数、结实率和千粒重的关系而获得高产。更多还原

【Abstract】 A field experiment was conducted with different transplanting densities(22.5×10~4,27×10~4 and 31.5×10~4 hole/ha) and nitrogen fertilizer rates(0,112.5,225.0 and 337.5 kg/ha) using an intersubspecific hybrid rice,Liangyoupeijiu.The main results were as follows:(1) Influence of transplanting density on panicle per unit area and grain number per panicle was higher than that on seed-setting rate and 1000-grain weight.There was no significant difference in yield between treatments with transplanting densities ranging from 22.5×10~4 to 31.5×10~4hole /ha.(2) Effect of nitrogen fertilizer on grain number per panicle was lower than that on panicle number,seed-setting rate and 1000-grain weight.Seed-setting rate and 1000-grain weight were decreased significantly in the treatment with 337.5 kg/ha nitrogen fertilizer.(3) The amount of N-uptake was increased with the increment of nitrogen fertilizer rate.But excessive N-content and nitrogen accumulation were not of benefit to the transfer of nitrogen from vegetative organs(leaf,sheath and stem) to panicle,resulting in the reduction of N-accumulation amount in seeds,seed-setting percentage,1000-grain weight and yield.(4) The better N accumulation of stem,sheath and leaf before heading,the better N transfer from stem,sheath and leaf to panicle after heading,the better coordinate relationship among panicle number,seed setting rate and 1000-grain weight and higher yield would be obtained under medium-fertility field with nitrogen application of 225.0 kg/ha,transplanting density of 22.5×10~4 hole/ha and high peak seedlings of 500.0×10~4/ha.更多还原