氮、磷肥用量对豫中地区大豆产量、干物质及经济效益的影响

为明确豫中地区大豆施肥中氮磷肥最佳用量，设置氮水平（0、60、120、180 kg/hm2）和磷水平（0、45、90、135 kg/hm2）大田试验，在大豆收获期，通过在每个小区取3个l m2进行测产，在大豆关键生育期每小区选取代表性植株3株，通过杀青、烘干测定干物重。结果表明，大豆地上部干物质量随着生育期不断增加，不同施氮水平下的大豆产量较不施氮肥处理增产9.01%~11.86%，不同磷肥用量较不磷施肥处理增产2.8%~12.0%；其中氮肥用量为120 kg/hm2、磷肥用量为90 kg/hm2时，增产效果最为明显，此时经济效益最佳。当氮肥用量超过120 kg/hm2时，会出现大豆地上部干物质量、产量下降，当磷肥用量超过90 kg/hm2时，磷肥利用率和增产效益都会出现下降。本研究表明，豫中地区氮肥用量120 kg/hm2、磷肥90 kg/hm2时，产量和经济效益最佳。

Nitrogen and Phosphorus Fertilizer Rate Affect Yield,Dry Matter and Economic Benefits of Soybean in Central Henan

To clarify the optimum amount of nitrogen and phosphorus fertilizer in soybean fertilization in central Henan, a field trial was set up, including nitrogen level (0, 60, 120, 180 kg/hm2) and phosphorus level (0, 45, 90, 135 kg/hm2). The dry weight was determined in the key growth period of soybean, and the yield was measured in the harvest period. Partial productivity, agronomic efficiency and economic benefits were calculated. The results showed that soybean aboveground dry matter mass increased with the growth period. The yield with nitrogen application increased by 9.01%-11.86% compared with non-nitrogen application. The yield with phosphorus application increased by 2.8%-12.0% compared with non-phosphorus application. The yieldincreasing effect was the most obvious and the economic benefit was the highest when nitrogen fertilizer amount was 120 kg/hm2 and phosphate fertilizer amount was 90 kg/hm2. When the nitrogen fertilizer amount exceeded 120 kg/hm2, the aboveground dry matter mass and yield decreased. When the phosphate fertilizer amount exceeded 90 kg/hm2, the phosphorus fertilizer utilization rate and yield-increasing efficiency decreased. Theresults indicate that the yield and economic benefit are the best when the nitrogen fertilizer application amount is 120 kg/hm2 and the phosphate fertilizer is 90 kg/hm2.