头季稻氮肥运筹对再生稻干物质积累、产量及氮素利用率的影响

为探讨头季稻不同肥料运筹方式对再生稻产量和氮素利用率的影响,以杂交稻组合"Ⅱ优航2号"为材料,在头季施氮量225.00kg·hm-2的基础上,研究了不同基蘖穗肥氮素配比3种基蘖肥与穗肥配比分别为8:2(N1)、7:3(N2)、6:4(N3)]头季稻-再生季稻氮素累积量、干物质生产、产量及氮素利用率的特性。结果表明:与N1、N2相比,头季成熟期N3处理氮素累积量分别增加9.26%、3.54%,头季齐穗期～头季成熟期N3处理氮素转移量分别增加21.47%、6.76%,整个生育期N3处理干物质净积累总量分别增加5.10%、4.78%。N3处理头季产量最高,达12431kg·hm-2,极显著高于N1、N2处理;氮肥利用率达46.44%,比N1、N2处理提高14.81%、5.43%;氮肥农学利用率达20.66kg·kg-1,比N1、N2处理提高14.97%、12.34%。研究结果还表明,头季不同基蘖穗肥氮素配比对再生稻再生季的影响不显著。

Effect of nitrogen application strategy in the first cropping rice on dry matter accumulation, grain yield and nitrogen utilization efficiency of the first cropping rice and its ratoon rice crop

The effect of fertilizer application strategy on nitrogen and dry-matter accumulation, grain yield and nitrogen utilization efficiency (NUE) of the ratoon rice crop and its first cropping rice was determined through designing 3 nitrogen applied proportion between basal-tiller dressing and panicle dressing 8∶2(N_1), 7∶3(N_2), 6∶4(N_3)] in the first cropping rice season with a constant nitrogen supply at 225.00 kg·hm~(-2) in the experiment. The results indicate that N accumulation under N_3 treatment is 9.26% and 3.54% higher at ripening stage of the first cropping rice than that under N_1 and N_2 treatments. Transportation of N from vegetative parts to panicle during grain-filling stage of the first cropping rice under N_3 is separately 21.47% and 6.76% higher than under N_1 and N_2 treatments. For the entire growth period, net dry-matter accumulation in rice under N_3 treatment increases by 5.10% and 4.78% compared with N_1 and N_2. For grain yield of the first cropping rice, N_3 treatment produces the highest (12 431 kg·hm~(-2)), which is significantly higher than that produced by N_1 and N_2. N utilization efficiency of N_3 treatment is as high 46.44%, 14.81% and 5.43% higher than that under N_1 and N_2. N agronomic efficiency in N_3 treatment is 20.66 kg·kg~(-1), 14.97% and 12.34% higher than in N_1 and N_2. Furthermore, the results show that different nitrogen proportion between basal-tiller dressing and panicle dressing with a constant nitrogen supply (225.00 kg·hm~(-2) N fertilizer) in the first cropping rice has no significant influence on the ratoon rice crop.