氮钾配合施用对亚种间杂交水稻养分吸收及产量影响的研究

氮促进亚种间杂交稻的分蘖和对磷、钾的吸收,钾也能促进氮、磷的吸收,但对分蘖似有抑制的趋势。稻株各生育期氮、磷、钾含量以分蘗盛期最高。随后迅速下降,至幼穗形成期下降速率减缓。齐穗后,累积在茎、叶的氮、磷大部分向穗部转移,而钾则很少运送到穗部。每生产100kg稻谷约需吸收1.71kg N、0.77kg P_2O_5、2.30kg K_2O,三者比例为1:0.45:1.35。氮、钾配合施用的增产效果大于单施氮或钾的效果;在施用量为82.5kg N ha~(-1)和75.0kg K_2O ha~(-1)的基础上,增施氮肥或钾肥,其增产效果相近,表明在施用适量氮肥的前提下,亚种间杂交稻对钾的反应甚为敏感。

EFFECT OF NITROGEN FERTILIZATION COOPERATED WITH POTASSIUM ON NUTRIENT ABSORPTION AND YIELDS OF INDICA-JAPONICA HYBRID RICE

Application of Nitrogen Fertilizer could enhance tillering and P or K absorption of Indica-Japonica hybrid rice. Potassium fertilizer would hasten the absorption of nitrogen and phosphorus, but might inhibit tillering. The highest contents of N, P, K in rice plant were appeared in the peak tillering stage, and decreased rapidly later. By the time of young ear formation the decreasing rate was slowed down. After heading, most nitrogen and phosphorus accumulated in stems and leaves were transfered into spikes, but the transfered potassium was only a little. 1.71 kg N, 0.77kg P_2O_5, 2.30kg K_2O were necesary to produce 100 kg grain approximately, the ratio of this three nutrients was 1: 0.45:1.35. The effect of applying nitrogen cooperated with potassium on the increase of rice production was larger than that of applying nitrogen or potassium alone. The effect of nitrogen addition on the yield was almost the same with the application of potassium based on the application rate of 82.5kg N ha~(-1) and 75.0kg K_2O ha~(-1), it showed Indica-Japonica hybrid rice was very sensitive to potassium under the condition of applying adequate nitrogen fertilizer.