为研究大豆叶面氮素的应用效果，以黑龙江省三江平原大豆主栽品种‘合农64’为试验材料，研究不同时期叶面施氮量对大豆叶片叶绿素含量及干物质积累的影响。结果表明，随着施肥量增加，叶绿素含量及干物质积累量呈现先上升后下降的趋势，不同时期普遍在B3处理达到最高值；A1时期叶面施氮有利于叶绿素含量及无籽粒干物质积累量增加，A3时期叶面施氮有利于籽粒干物质积累及产量形成。在A1B3处理组合下大豆叶片叶绿素含量最高，SPAD值为49.30；在A3B3处理组合下籽粒干物重最高，为26.08 g。因此，就‘合农64’这一品种而言，利于产量形成的最佳处理组合为A3B3，如果在A1B3和A3B3都进行处理，产量结果可能会更高。

For research the effect of soybean nitrogen foliar application, using Sanjiang Plain in Heilongjiang soybean cultivar ‘Henong64’ as test materials, Effects of chlorophyll content and dry matter accumulation were investigated on different period and leaf nitrogen application on soybean. The results showed that, chlorophyll content and dry matter accumulation first increased and then decreased as fertilization increased and had the highest value in B3 in different period. Leaf nitrogen application in A1 period conducive to increasing the chlorophyll content and dry matter accumulation without seeds and in A3 period to the dry matter accumulation in seeds and yield. The chlorophyll content had the highest value in A1B3 with 49.30 SPAD. The dry matter accumulation in seeds had the highest value in A3B3 with 36.08 g. So in terms of ‘Henong64’, the best treatment combination was A3B3 conducive to yield. If treatment had been done in A1B3 and A3B3, the yield would be better.