不同时期施用氮肥对大豆根瘤固氮酶活性及产量的影响

采用框栽的培养方法,设置同一氮肥水平,按不同生育时期施用,对大豆植株生长过程中根瘤固氮酶活性动态变化进行研究。结果表明,减少基肥的施用可以降低对根瘤生长的抑制作用,使得固氮酶活性峰期后移,延缓后期大豆根系及根瘤的衰退,促进生长后期养分积累及干物质积累,促进成荚、鼓粒,产量比一次性施肥有所提高。鼓粒初期追施氮肥较一次性施用氮肥产量提高3.33%,在花期和鼓粒期追肥及荚期追肥增产效果不显著。

Effect of N fertilization at different stage on nitrogenase activity and yield of soybean

The changes of root nodule nitrogenase activities at different growth stages were studied with pot culture method and 4 fertilization modes. The results showed that decreasing N fertilizer rate at seeding time could reduce the inhibitory effect of nitrogen on root nodules, shift nitrogenase peak-hour rearward, delay root system and root nodule retrogression, promote nutrient and dry matter accumulation, promote pod bearing and filling, and increase the yield. Compared with basal application, topdressing N in early pod filling stage, the yield increased by 3.33%. The effect of topdressing N on soybean yield in batches or at pod bearing stage was not sig-nificant.