钾对玉米叶片物质代谢及产量的影响

以严重缺钾土壤（速效钾48．8ppm)为介质进行玉米盆栽试验，将土壤配成低，中，高3个钾水平，氮，磷等其它肥料施量相同，测定玉米叶片中物质代谢以及产量。结果表明：低钾处理的植株叶片中可溶性糖含量低，尤其是缺钾症状严重的下部叶片外缘可溶性糖含量更低，但淀粉积累，钾能增加叶片中蛋白质含量，但过量施用钾肥则蛋白质含量下降，适量钾肥可使叶片中脯氨酸含量增加，丝氨酸含量下降，过量钾肥使叶片中游离氨含量增加，产量结果是：适量钾肥比低钾增产31．4％，比高钾增产9．10％，高量钾比低 增产20．5％。

The Effect of Potassium on the Leaf Substance Metabolism and Yield of Maize

The pot culture of maize was undertaken with the K-deficientsoils which involved three K levels but similar content of other elements.The leaf substance metabolism and yield were measured.The results showed that the soluble sugar content in the leaves of plant trated with low K was lower,particularly in the lower leaf margins with serious K-deficiency symptom,but starch accumulatedo K increased the protein in leaves,but excess K decreased it.Proper amount of K fertilizer increesed the proline,but decreased serine content in the leaves.Excess K caused the free amonia to increase in the leaves.The yields were such:proper K was higer than low K by 31. 4%,and higher than excess K by 9. 10%;excess K was higher than lowkby 20. 5%.