氮、钾不同营养水平对春玉米氮代谢的影响

采用田间小区试验方法研究了氮、钾不同营养水平对春玉米氮代谢的影响。结果表明：氮代谢指标(可溶性蛋白、硝酸还原酶、谷氨酸脱氢酶)在整个生育时期内呈单峰曲线变化，即从苗期开始逐渐增加，达到高峰后又呈下降趋势，成熟期最低。可溶性蛋白含量在抽雄吐丝期达到最高峰，硝酸还原酶和谷氨酸脱氢酶活性在大喇叭口时期达到最高。各生育时期，氮代谢关键酶活性及可溶性蛋白含量均表现为随氮、钾营养水平的提高先增加后减少的趋势。表明适宜氮、钾肥用量可以增加叶片可溶性蛋白含量及提高硝酸还原酶和谷氨酸脱氢酶活性，过量施用氮、钾肥反而会使其含量或活性下降。

Effects of Different N and K Levels on Nitrogen Metabolism of Spring Maize

Study on the effects of different N and K level on nitrogen metabolism of spring maize was carried out by field experiment. The result showed that the main indexes of N metabolism in maize leaves(content of soluble protein, NR and GDH) showed a single curve at the whole growth stage, and the peak value period of soluble protein was present in the heading stage, the peak value period of NR and GDH was present in the large bell stage. The main indexes of N metabolism was increasing and then decreasing following the increasing apply of N and K. it was concluded that the moderate N and K nutrition levels could keep relative higher content of soluble protein, NR, and GDH, but overabundance could get the contrary result.