增施钾肥对冷浸田水稻生理及植株铁吸收累积的影响

Effects of Potassium Fertilizer Increasement on Rice Physiology and Iron Accumulation in Cold-waterlogged Paddy Field

有效钾缺乏、Fe2＋毒害是影响冷浸田水稻产量的重要因素。通过田间试验，研究不同钾肥用量对冷浸田水稻生长生理、植株铁累积及产量的影响。结果表明：与不施钾肥相比，增施钾肥孕穗期水稻叶绿素 a＋b 和光合速率分别增加10．27％～28．40％、11．40％～29．31％，孕穗期与成熟期根系活力分别提高10．53％～22．67％、27．71％～48．62％，成熟期稻谷产量增加4．93％～14．77％。施肥能促进植株体内钾的吸收和抑制根系对铁的累积。在水稻分蘖期、孕穗期与成熟期，根系铁含量分别降低0．04～0．73、0．33～0．95及0．62～0．82个百分点，此外在分蘖期水稻根系钾与铁含量呈极显著负相关（r ＝－0．86＊＊）。增施钾肥能够提高根系活力，增强光合作用，促进碳水化合物合成与运输，同时较好地抑制铁的累积，因此增施钾肥是发挥冷浸田生产潜力的有效措施。

Shortage of effective potassium and toxicity of Fe2＋ are important limited factors to rice yield in cold-waterlogged paddy field.Based on the field experiment,the effects of rice growth physiology,plant potassium iron nutrient accumulation and rice yield components were studied in cold-waterlogged paddy field under different potassium utilized in the paper.The results indicated that the content of chlorophyll a＋b and photosynthetic ratio could respectively improve 10.53% ~ 22.67%、27.71% ~ 48.62% in booting stage under potassium fertilizer increasement,10.53%~22.67%、27.71 %~48.62% for root activity improved respectively in booting stage and mature stage.Meanwhile,rice yield could improve 4.93%~14.77%.Potassium fertilizer increased could not only promote the absorption and transportation of potassium,inhibit the iron accumulation of rice root,but only could reduce respectively 0.04~0.73、0.33 ~0.95 and 0.62 ~0.82 percentage point for the content of iron in tillering stage,booting stage and mature stage,indicating that it was a significantly negative correlation between rice root potash content and iron content in tillering stage.Potassium fertilizer increasement could improve the root activity, strengthen the photosynthesis,promote the synthetic and transportation of carbohydrates,inhibit the toxicity of Fe2 ＋ .So potassium fertilizer increasement could play the production potential for cold-waterlogged paddy field.