铵态氮肥施用量对春小麦氮代谢的影响

Effect of Ammonium Nitrogen Fertilizer Dosage on Nitrogen Metabolism of Spring Wheat

为了揭示铵态氮肥施用条件下春小麦的氮代谢机制,为春小麦生产的合理施肥提供理论依据,采用盆栽试验,设置4个氮素水平,研究不同用量铵态氮肥的施用对春小麦不同生育时期叶片氮代谢的影响。结果表明,小麦叶片硝酸还原酶、谷氨酰胺合成酶和谷氨酸合成酶活性随着施氮量增加呈先上升后下降趋势,脯氨酸含量随施氮量的增加而上升,可溶性蛋白变化无明显差异;铵态氮肥施用量在225kg/hm2时,小麦叶片中硝酸还原酶活力、谷氨酰胺合成酶活力和谷氨酸合成酶活力达到最大值。结论:适当增加铵态氮肥有助于小麦叶片的氮代谢,但施用过量就会使根系酸化,破坏小麦叶片的氮代谢。

To reveal the metabolic mechanism of nitrogen of spring wheat applied with ammonium nitrogen fertilizer and provide a theoretical basis for rational application of fertilizer in spring wheat product,a pot experiment was conducted to study the effect of different dosage of ammonium nitrogen fertilizer on leaf nitrogen metabolism.The results showed that activities of nitrate reductase,glutamine synthetase and glutamate synthase increased first and then declined with the increase of nitrogen dosage.Proline content increased with the increase of nitrogen dosage,however,the soluble protein content had no significant change.Activities of nitrate reductase,glutamine synthetase and glutamate synthase in leaf reached the highest when the dosage of ammonium nitrogen fertilizer was 225 kg/hm2.It was concluded that appropriate dosage of ammonium nitrogen fertilizer was beneficial to leaf nitrogen metabolism of spring wheat,however,the root system would be acidized and the leaf nitrogen metabolism would be broken if applied with excessive amount of ammonium nitrogen fertilizer.